I guess because for some it might look boring?
Also Bloom and crisp graphics aren't mutually exclusive, imho.
Looking at it from another perspective, I think these effects are producing something like "hyper-reality".
Similarly to HDR-effects in photography, strong bloom and/or HDR effects in games seem to make them look more "real", although in reality they look less real, as it often is completely overdone. Nevertheless it's an gimmick that's en vogue right now.
(Same with "god-rays". Have you ever seen something like this on the scale it's being used in games? You would probably need tons of vapor or dust in the air to even remotely have such a pronounced effect. )
Anyway, I don't care much for the presence or absence of such effects, if the arts are good overall. I agree that overdoing it hurts the game, but if done right (usually meaning not using too much) I feel it can "spice up" the graphics a bit.