Would it really be any different if the issue was race and not gender? I seem to remember this being a problem after Jackie Robinson made the major leagues (at least one team threatened to strike over that). Would it have been so principled for opposing teams to refuse to play against a team which had a black player?
SO I guess you would be cool with a man fighting a woman in a 3round, 5 minute, cage fight UFC style?
Basically what I'm getting here is that a bunch of people are in favor of watching men beat up women, am I wrong? This certainly isn't "sparring" in karate or something, this is competitive combat sport. And if you are ok with wrestling than I assume you are ok with caged fights were people get concussed and broken bones frequently.