1. Past is relevant, because what's happened since Cata is eerily similar to what happened between Vanilla and WotLK. Means there's a pattern here that can be identified and hopefully avoided.
2. We can not control Blizzard. We can try to influence them; I know I tried pretty hard to influence them at some point. They didn't start even talking to the twink community until about 2 months after I quit.
3. We can control ourselves, and we can influence each other. It all depends on what you want out of WoW. You want games? You got em at 20-24. You want them in other brackets? Network with other players and lend your support to players who have connections and the ability to contact and influence others. You want to win games? Improve your skill as far as you can, then find teammates who are skilled or train them to be skilled, and practice until you can beat anybody. You want to just chat or complain about how things are now? Well, you already get to do that.
4. A lot of people claim certain things aren't possible when they're really just difficult, or take time. WoW used to have more things like that back in the day, but twinking still sometimes takes a lot of investment. A part of twinking came out of players proving that some things in this game actually were possible when people said they weren't. That usually is attributed to things like getting certain achievements, or titles, or making certain class/spec combos work. But it also applies to communities and organization. Those people who resurrected brackets, or even just organized large scale events that were thought impossible to pull off are rightfully revered for what they did, but it's actually much more doable that people seem to think. You don't have to be special or something to do it, especially not in this game. You just have to try, and keep trying until you learn how.