I think it's like anything in art. When used with an intent and employed skillfully, it can help express the emotion behind the image. When over used or misused, it can help create garbage....

I agree with your mystical poster that I see many images that are way too high in contrast and saturation - so much so that that's the only thing I see. I'm kind of thinking this is becoming more common. Many digital photos I see online are too saturated and contrasty. Many consumer electronics display images that are too saturated and contrasty.

Personally, I like subtle tones punctuated with areas of good to great contrast.