Whats with these "non-greasable" tie-rods,ball joints ect?

why do they factorys equip. these cars without grease zurks/fittings for the tierods and ball joints? I go to grease and surprise, its all these contained grease boots without a fitting. Is this an environmental things so your car won't drop a dollop of excess grease on the ground? Or a way to get the owner to have to buy new tierods and ball joints every 75 thousand miles....