It's not just healers, it's the entire game. Somewhere along the way someone decided every class needed to be able to do everything (I guess for raiding purposes?) and it's never been the same since.
It's hard to have a strategy game when everyone is so similar. In a well-designed game, different archetypes/strategies have a very different set of strengths and weaknesses. Good players can maximize the value of their strengths while mitigating the impact of their weaknesses. When pitted against a lesser player, they will be able to successfully exploit the weaknesses of their play/strategy while protecting the weaknesses of their own. For example, a good SC2 player will take clues from the enemy base and suspect a dark shrine rush, scout the map for the dark shrine, and prepare detection for the templar to take minimal damage, then counterattack a couple minutes later with a force that the other player can't handle because of heavily investing in an ineffective tech rush. This is the essence of a strategy game - capitalizing on strengths (scouting, defense) while exploiting weakness (getting scouted on a risky cheese strat).
In arena there's no such interaction. A jungle cleave runs in and pops every cooldown on their kill target, and then if you manage to survive, they remain just as strong as you throughout the rest of the game, and then become super saiyans again in 3 minutes. This is the equivalent of getting 6 pooled, defending it with minimal losses, then counter attacking 3 minutes later with a bio ball only to find that he has 35 roaches already and mutalisks in your mineral line. It's the equivalent of dropping a turn 2 undertaker combo using your entire hand, getting shut down, then just dropping dr. boom on turn 3. It's nonsense, it's not a game, it's amateur shit. There's no fucking weakness anywhere, there's no counterplay, there's no skill. Back when wow was the only game on the internet I used to pray that more games would come out and challenge its throne, force blizzard to elevate their game. Well that shit has come and gone, and instead they've done absolutely nothing, maybe even gotten worse, as they sit here and watch their flagship game slowly wither and die. It's extremely disappointing.
I just noticed but the teams that are chosen and players that are accepted are all involved in skill-capped. I do not know if anyone else thinks it is kind of wrong that neilyo and others were not allowed in the tournament because they do not back or support skill-capped. I just think all players should be given an equal opportunity when entering these tournaments, all players in it are in their own little clique. Just thought I would give my two cents about it and was wondering if anyone else agrees, also I heard about a new site that is supposed to trump skill-capped I do not know if it's true or not though.