I'm going to reply to this but it's also a response to @Magnosh as well.
If the outcome in both scenarios -- either deterministic rewards or RNG-influenced systems like Corrupted gear and TFing -- is that people quit the game, what is a developer to do? If they listen to the hateful forum masses, the game goes back to the way it was and suddenly there are fewer people engaged in content and subscriber levels plummet. If they don't listen to the hateful forum masses, they're tone-deaf idiots who intentionally do things to piss off their playerbase. It's a lose-lose for the developers.
The only real solution is to do what they have been doing: Not taking full measures but instead building incrementally on existing systems. Forum posters will always be in favor of full measures because they have romanticized feelings about whatever version of WoW they personally felt was "perfect," but the reality is that what's perfect for one player was a shitshow for many others. And it's Blizzard's job to listen to the playerbase as a whole and not just the ones who have the strongest, loudest opinions. I will once again agree that it's unfortunate that WoW has become this weird amalgamation of many different carefully-thought-out systems designed to keep players engaged, but I don't see how WoW could continue to exist otherwise. The MMO boom ended a fucking decade ago and Blizzard must be doing something right to keep the game alive and profitable this many years later. For that alone, I think they deserve the benefit of the doubt.