They take features that don't really make sense on a character and cram it on
Body hair would look aesthetically better on, let's say, an older man/woman, probably workers or bodybuilders of some sort.
The same thing goes for fat and such due to younger people (most commonly seen having fat in sjw art) not having a developed enough body (17~ is when you start growing body fat in substantial amounts, while most characters they draw are at least 14.)
Vitiligo isn't throwing splotches of white skin randomly to make them look like The Human Cow, its gradual loss of pigmentation so it's going to be uneven and messy sometimes instead of perfect shapes.
Stylistically, I think the "tumblr sjw style" noses would be cuter on simpler drawings/figures like Animal Crossing villagers or mii's, instead of legitimate humans. Sausage mouth is just lazy, go back to California.
