American women shaving their pits only goes back to the 1920s which is also when facial hair was becoming far less fashionable for men. Brief and limited returns to it have happened like with the hippy culture, but I don't think it will fully take off again, at least here in America. Having dated European girls while in the service hairy pits doesnt bother or shock me one way or the other, but let's not go all my little pony over it and give it color. Though if green it will give those Chia Pet people another product to sell.