What's insulting here is that Zuck is trying to keep the "hoodie-guy" image despite his unimaginable wealth. You can't have the cake and eat it.
A very rich guy persists in wearing the hoodie he wore while doing the work that made him rich? Where do you see hypocrisy there?
Some people just rebel against the "norm" of using clothing to represent their socioeconomic status - money or no money.