Because of biological programming. Humans are the only mammals with females that have permanent boobyliciously boobing boobies, so as per evolution it is no surprise that human males are going boinks for them. Size, shape, motion, who they be on are the mutual factors for any attractive body part, quite so also for boobs. They are cute when tight and jiggly, pretty when bouncy and cozy to feel up regardless of size, neat to catch a stolen glimpse and satisfactory to blblblblbl.

I don’t know what kind of shocking reveal you expect.