I'm sure the original height and weight requirements were set up, not to discriminate against women, but because applicants of a certain size were necessary to carry someone out of a burning building, lift a ladder or haul a stretcher.
I've worked with some big tall fat guys who couldn't carry their laundry. I've also worked with some little scrawny asians who could pick me up and carry me up a flight of stairs. Ever watch olympic weightlifting and seen a little bulgarian lift 500 lbs? Would you rather have that guy on your fire department or Michael Moore?