Ehm. While I somewhat agree with your first paragraph (that's still not "fine" btw), saying that there's nothing special about corals is kinda bullshit. About a quarter of other marine species in those areas depend on those during at least some part of their lifecycle. And not just snorkelling-pretty fish, fish that we catch for food in areas with coral reefs also heavily rely on them. Bleached corals is not a coral problem, it's a marine ecosystem problem.

Also, evolution doesn't really work on timescales of mere years. Substantial changes take millennia or even eons.