I think it's women's clothing. Samuel R. Delany tells a story in one of his essays about the time his wife, Marilyn Hacker, got soaked by rain coming home, and put on a pair of his trousers since that was what they had clean, and was totally astonished by the roomy, comfortable pockets. Delany's point was how unaware we are of the cultural restrictions we live under.

For my part as a man, I need my large pockets because they're the only place I have to carry the things that women put in purses.