Doing more than one thing isn't doing 'everything', Shuma. Stop exaggerating so that it supports your argument. There's nothing wrong with classes being able to do something else than their primary purpose. Having one-trick pony classes may make balance easier, but it doesn't make the game more fun. Every class should have an alternative role, and like I listed about, most already do. Only the Doombringer and Sentinel really struggle in terms of branching out. So those classes have it right and we should just scrap and start over with the rest?
Wait, don't answer that, I think I know what your answer will be.
I think it's obvious we won't agree here, so how about let's just drop it so this doesn't go on forever. You think Sentinels are fine, I think they need relatively minor changes. There you have it.