I have nothing against unshaded skins, if they look good. The problem is that many of them look a bit cheap, but hey, using a skin is like wearing clothes, it expresses your personality and mostly your taste, so nothing against them, really!
Personally I prefer shaded skins, but not over shaded. I think some plasticity is really good, and when I do my skins I shade what I think is right for that skin. I never go extremely far in details because some heavily shaded skin do really look like a cluster of pixels to me, I agree with Cooper on what he said.
The point of the effort, well, that's a personal opinion. I myself don't take much to make a skin, mostly because I do them for myself, and later upload them on here. no more than 3 of my skins took more than a day to do. But that is a choice of the skinner.
Finally, nothing should be bashed, unless there is a good motivation. Things like "oh it's unshaded! It sux!" are always stupid and pointless, just like "that kind of music sucks".
