I usually view people running substandard builds in dungeons to be selfish. .
Why is non-Zerker considered sub standard? Because it has lower damage numbers? Meanwhile, you have four warriors all running the meta zerk build, with zero condi clears - leaving it up to whoever isn't running the standard to cover their asses.
Efficient does not equal optimal, or what should be considered the standard. But again, when dealing with a pre-organized five man designed from the ground up to farm a dungeon via speedclears, sure. But I'm talking about general play, about the community, about seeing all the dead zerkers in PvE, and the ragequitting zerkers in dungeon pugs because they all wiped at Spider Queen.
I think the zerk meta is, in the long term, harmful - but I'm not saying people should stop running zerk. I think the onus is on ArenaNet to up their game and design better content that makes stacking cheese tactics and "kill it before it kills us so we don't have to bother learning how to fight it right" impossible.
But that's me. I'm coming from a "I finished Bayonetta on Infinite Climax difficulty" viewpoint - where the point of the game isn't to farm for shinies, but to
play. I realize people have different reasons for playing: some only care about the shines, some care only about getting money, some only care about getting through everything as fast as possible so they can be "done" with it, and so on. And that's all fine. I guess I just find it a pity, because it is, to me, ignoring the entire point of what a video game is.
I dunno, my thinking on this is fuzzy at the moment.