Because heaven forbid the actors and other industry professionals pressure Alan Horn into reconsidering his decision. Nope, it's a semi-obscure critic and laughing stock from the entertainment wasteland that is the Boston area.
Off topic, but with Bob's endless fellatio on the MCU, it does make me wonder if HBO would've been a better medium for Justice League (albeit with the right show runner.) Comics are--at their heart--a serial medium and I see film as limiting in many respects. Case in point, the Scarlet Witch/Vision romance was barely a subplot in Civil War, but it gains significance in Infinity War because... Infinity Stone? GoT was better at handling a larger cast though the longevity of its characters has become something of a joke. Like hiring George R. R. Martin as your wedding planner.
I guess we'll see how well HBO and capeshit mingles when Watchmen comes out later this year.
IIRC Watchmen2 was forced upon HBO by a combination of Time Warner/ATT.
Time Warner has always been pissed that DC Comics big-wig Paul Levitz explicitly refused to whore out the Watchmen franchise outside of the movie. When Levitz stepped down from his position of power at DC. Warner forced his replacements to start whoring out the Watchmen franchise, culminating with the TV show.
AT&T meanwhile, has started micromanaging HBO and demanding they basically become more like network TV because AT&T doesn't like the fact that HBO historically has subscription problems where people subscribe for a month or two for the purpose of watching a single original show (like Game of Thrones).
AT&T basically wants HBO to start showing original programing seven nights a week, like a normal network TV station. And for them to abandon their "quality over quantity" rule and flood the channel with new programming to fill the 7 day a week primetime schedule. Hence them going along with forcing Watchmen2 on HBO and also, doing stuff like signing Joss Whedon to a long term contract to produce new shows for HBO. I would also fully expect them to eventually start airing Doom Patrol, Titans, Swamp Thing, Star Girl, and other DCUniverse streaming shows in the future, especially if the streaming site eventually gets shut down.
That said, Watchman's a sequel series with a cast that is full of SJW garbage and only one returning character (Adrian Veidt). Rorschach is supposed to be more or less a cult thing in the revival and the rest of the cast outside Veidt is SJW themed created by committee Donut Steel characters.
And worse than that, it's going to come across as even more of a soulless cash grab/INO show with Watchmen references shoved into it, because DC is right now publishing the OFFICIAL Watchman sequel (Doomsday Clock), which invalidates the premise of the TV show, in that it provides a canon explanation as to what happened after Watchmen ends (Adrian's plan fails, gets exposed within half a decade, and Russia decides to nuke the US with Adrian faking brain cancer to get sympathy points from his new henchmen gang as they go to the DC Universe to try and get Manhattan to come back and save the day).