While I clipped most of your message I did read the whole thing. Granted, my experiences as a hobbyist has dealt mostly with friends who enjoyed debating both mine and their own interpretations of a setting (depending on what we were playing). I have no idea how much it sucks to have to deal with that shit from some random stranger who may or may not be willing to give your interpretation any credit and insists on just Rules/Lore Lawyering straight down to the bottom.
Even though I've read up a bit on Warhammer 40k, I'm definitely no expert. I just found its justification for inconsistencies unique. Despite the problems that may cause.
On the offically published end, that's kind of missing exactly what I tried to point out in the first place. Assuming you aren't playing with complete lunatics like That Guy you can just kind of pick whatever you want as long as its brought up first. Granted, I'm appreciating it from a distance. I've invested about $20 into Warhammer 40k and that was because I got a favor from a buddy. I've never spent $400 and then had to play with a dickwad who insists on sticking to current rules no matter how bullshit they are.
Understandable. I can see how to someone who hasn't made any real investment in the game it may seem appealing. Warhammer's lore has survived from staying mostly true to itself rather than compromising elements just to appeal to outliers.
However, Space Marines weren't always at the apex of their attentions; they still received a great deal of lore - yes, but it was much more interspersed and model releases were more consistent for everyone. The only guys that truly received no love for the longest time were the Dark Eldar and Sisters of Battle.
Nowadays it's feeling more than just a little ridiculous how much focus has been placed on the Astartes. The Eldar on both sides just received
one update to a special character model each, compared to GW farting out what? Something like 6-8 Primaris character revisions this year? They have so many bloody special characters they could form their own standing army. Why has it taken so long just to update
one Phoenix Lord? And that's to say nothing of how long stuff like the Avatar of Khaine has been sitting around with the same design for decades. It just really feels inconsistent and unfortunately, you can expect updates of updates of updates of some SM models before you can expect some for the more neglected xenos.
The focus on Space Marines gets even sillier when you realize they are by far the smallest faction in the game. And, when written correctly, they should come across as downright alien. I've often thought it goofy that the loss of the Ultramarine First Company was portrayed as this dramatic thing, but it was only like a hundred guys, right? It ain't exactly D Day.
It is kinda ridiculous. It's meant to evoke a Spartan sort of feel, but that's lost amidst just how much they receive. Lorewise they're only supposed to be like a thousand soldiers per chapter, but they keep getting special squads and Primaris upgrades and all the new cool, funky gadgetry that one wonders if they really are small anymore.