>>773167They look natural and more imperfect.
Make-up is pretty much covering up imperfections, which makes the whole appearance more "stylized", the same reason why anime ckicks are always percieved as so perfect, because in 2D land there are no imperfections, skin is always clean, silky smooth etc. unless it is there for emphasis.
Now how you see this is a personal thing, but keep in mind that the appearance in person also is completely different than in a still photo, live they often look much nicer.
