Pruning the defensive cds and sustainability of dps classes killed this game for me. Hybrid dps like Balance/Ele/Spriest can't off heal like they used to and feel like you're playing a Warrior. By pruning or nerfing dps survivability has made the healing role way more powerful and dps are now designed to be dependent on healers for the game to function.
Duels and random bg pvp is horrendous as a result of this. Every dps spec just feels exactly the same. Most specs only have one shield wall or a block or something stupid like Karma but that's about it. There's no more days where a good Mage can get a good Evocation off and heal to full or a Ret that can keep his Warrior partner alive with off healing support in 2's. 2's is actually a good example on how bad this problem is because 90% of specs have to play with a healer or else its auto lose. And the other 10% have to work 100 times harder to win over a dps/healer team that just has to pve their way to victory.
Game is just dominated by the healing role and the ability level of the healer. This game revolves around an unpopular role that only a handful of people enjoy. It's no wonder arena participation is so low. There's no games because there's a shortage of healers because most people don't want to heal.
The solution should be to make dps more self sufficient which puts less responsibility on the shoulders of the healer. I'd also like to see healers more dps/cc oriented rather than just passive pillars of immortality.