Why do girls think that boots/ugg boots make their legs look y?

Yeah, I don't get the Ugg fad either, except for the fact that they are very comfortable. Feels like you're wearing slippers. But I agree, they should not be worn with shorts, or short skirts. Knee-high, regular, (non-Ugg) boots, can look cute with a short skirt if they are paired with textured, opaque tights. Bare-legged, it just looks tacky.