Just why is/was Bendis a big deal? I'm not a Marvel reader so I've not come across his stuff there, but just how was anyone excited for his stuff?
Bendis came to fame around 1998-1999 with Powers (one of his first books ever) which is a huge case of "series where the only installment ANYONE remembers is the first, IE Who Killed Retro Girl); the first arc had a bunch of pot shots against John Byrne back when Byrne was at the height of fans hating his guts as this was when Byrne's franchise killing Amazing Spider-Man, Hulk, and Wonder Woman runs were all running at the same time. Ironically, Bendis has a huge obsession boner for Byrne's work and DESPERATELY wants Byrne to collaborate with him, though Byrne is an elephant when it comes to remembering and carrying grudges and refuses to work with Bendis due to those early pot shots he made in WKRG.
Bendis further added to his "street cred" when he quit Todd McFarlane's stealth movie pitch book "Hellspawn" (basically a side story retelling of Spawn with a white guy instead that was done to drum up interest into a film reboot) when McFarlane demanded Bendis insert Miracleman (who Todd had just bought, but not really as everyone later found out) as part of Todd's war with Neil Gaiman over Miracleman and Angela. Bendis quitting Spawn led to Todd firing him from another book Todd put out (Sam And Twitch), which along with Powers, was what got Bendis noticed by comic fans.
The first sign of Bendis being failure and AIDS came with his first major Marvel work: a short run on Daredevil that featured his first butchery of canon and lore and continuity. The story had Frog Man; a joke Spider-Man villain who reformed and who's chief character trait was that he was a great dad who would do ANYTHING to protect his son (who secretly was using his dad's costume to fight crime from time to time), who Bendis decided was an evil incarnate abusive father who tormented and brutalized his son (now about 5-6 years old rather than in his late teens) until Daredevil beat him up and helped Ben Ulrich gain custody of the kid. The story was WIDELY reviled, made worse due to the fact that the Spider-Man editorial staff (unknowingly) commissioned a story for a new anthology Spider-Man book of theirs, at the same time and refused Bendis's demand that the story never see the light of day, due to the fact that it featured Frog Man and his son as they had been prior to Bendis's story. The Bendis frog man story was so reviled that Marvel basically had to declare it non-canon and banned Bendis from referencing it as he got yanked from Daredevil for about a year before being let back onto the book.
In the meantime, Marvel was working on launching their "new universe for casuals" Ultimate line and Quesada pitched and got Bendis the Ultimate Spidey job. It did come with controversies (Bendis demanded Mark Bagley draw the book and had Quesada, by now Editor In Chief, threaten to blackball Bagley if he didn't take the gig). But between the dire nature of the Spidey books under Byrne, Mackie, and JMS's own controversial first year on the book, a huge hit with jaded Spider-Man fans and it had one thing that made it must buy: it was the only book where Mary Jane was allowed to appear as Quesada and JMS embargoed the character and Quesada was plotting to get Kevin Smth to write the story where MJ divorces Peter after he realized JMS had no intention on finalizing the end of the marriage.
This was the ultimate reason WHY Ultimate Spidey got so much praise. It was 100% the MJ/Peter shippers hyping it up and then some because it was the only place MJ was allowed to show up and be with Peter. To the point that once MJ was brought back full time in ASM #50 by JMS,
Bendis stopped pandering to said shippers and broke MJ/Peter up in Ultimate Spidey to forcibly promote his crack ship of Kitty Pryde/Peter. Because Bendis's anti-life ideals (which culminated in Peter dying because that was the only happy ending he could have, given that it was a running subplot that Ultimate Nick Fury was going to kidnap Peter on his 18th birthday and basically make a black ops slave out of him, making him do all sorts of illegal wetworks shit ala the Weapon X project and that they even made a female gendered clone out of Peter, because Ultimate Fury couldn't fucking wait to have Peter killing for him and made a female version of him to do bad shit for him).
But his proper DD/Alias runs were also runs that were full of Bendis getting some pushback with editorial that made him be resentful that he was told "no" and added to him becoming the industry's version of Angelica Pickles. Alias was supposed to be Jessica Drew (the original Spider-Woman) but got vetoed because the first issue would have had Drew getting butt-fucked by Luke Cage and curse (something Tom Brevoort didn't want happening because of his own waifu fetishization of Jessica Drew). He also wanted to kill Ant Man off, even though Scott Lang was heavily being featured in Avengers and defied Geoff Johns/Brevoort by writing Scott's death and being made, against his will, to have to rewrite the following issue when they realized he openly tried to derail Geoff's run on Avengers (which started off the rivalry and Bendis's general desire to fuck up anything and everything Geoff does out of spite and why the VERY FIRST THING he did on Avengers was kill Scott Lang off and nearly starting a war with Disney when they ordered Scott brought back to life after Bendis cockblocked anyone from bringing him back for nearly half a decade, by having Matt Fraction conspire to kill Scott off again in Defenders). Meanwhile, he also tried to kill Kingpin off with a Mary Sue character carrying out a coup against Kingpin as part of Bendis' usual MO of creating original characters who are better than the existing character they are replacing and shitting on the existing character while he's killing them off at the hands of his OC) which pissed off the Spidey editors (since DD and Spidey share Kingpin), forcing him to rewrite his arc to have Kingpin live and ending his run with another OC basically shitting on Kingpin when he sends DD and Kingpin to jail.
By 2004 Bendis was consolidating his behind the scenes and online powers and Brevoort, after a string of flops that basically threatened to cost him his Avengers editorial fiefdom, basically surrendered to Bendis when Bendis demanded to write Avengers and murdered half the cast and irrevocably destroyed Scarlet Witch twice over. His Avengers run also saw Bendis pull a Gamergate style online censorship campaign as his sycophantic legion of online fans basically had hijacked control over nearly ALL of the major comic message boards and made it a bannable offense to say ANYTHING critical about Bendis and his rape of the Avengers and the collatoral damage he inflicted upon the X-Men in House of M.
His Avengers run itself was a paper tiger though as he demanded a huge number of variant cover schemes to artificially inflate his sales numbers, combined with Bendis demanding every single X-Over (which at the time, had been embargoed by Quesada but brought back for Bendis) going forward being Avengers specific to artificially inflate his sales. Ironically this caught up with him as his run kept getting worse and worse and worse and by Secret Invasion, normies started to realize how badly Avengers sucked under Bendis and Marvel had to break and finally start putting out non Bendis written Avengers books to stem the backlash. Even to the point that other writers started standing up to Bendis and the cowed Brevoort; when Bendis tried to destroy the climax of the Abnett/Lanning Marvel Cosmic line by stealing Thanos from them/banning them from using him, since Bendis wanted Thanos to be the "secret weapon" Norman Osborn was using to have his super-villain cabal follow him, they threatened to go public and ruin the big reveal Bendis was going to have, to force Brevoort to take their side and block Bendis. Which Bendis never fucking forgave, as he took over Guardians when they left and shitted all over them and Thanos and even made Marvel put it in his contract, Bendis having the right to fuck over any future writer as far as him having ultimate control and first dibs on ANY character in the Marvel line, other writers using them be damned. Which led, ironically, to the only good thing Slott did in his Spider-Man run as he objected HARD to Bendis wanting Peter Parker to die in Civil War 2 in order to force Marvel to make Miles the only Spider-Man in town and Marvel was forced to side with Slott, given that Slott had his own deals in place predating Bendis' deal with regards to controlling Spidey in exchange for towing the pro-One More Day line with Spidey.
In short, Bendis is a writer who's career is largely based on shitting on John Byrne back when it was fashionable (and kind of deserved) and pandering HARD to the MJ/Peter shippers, but he became a monster in part because he doesn't give a shit about anyone but himself since he first step foot at Marvel and carrying MASSIVE grudges over early instances when editorial rightfully told him "No!" while cultivating a fanbase of white knights who do their best to censor/ban ANYONE who says anything negative about Bendis online.
