More likely, because western society demands it.
"D*mn, bud'! Cover that hairy back with somethin'! I'm about to lose my lunch! And let's not even get into the deal with that plumber's crack!"
I have a friend who frows hair so fast he has to shave twice a day, and to be presentable with a polo shirt with the neck open, he shaves around his neck and about 6" down his chest.