Well theres some doctors organization thats against legalization of both professional mma and professional boxing. They're lobbying pretty hard to get it banned again.
plus we had some guy, Ken Hyashi; something like that, chairing the ontario athletic commision and he said mma violated our criminal code(which u COULD make that agrument, based on glove size vs prize fighting, something like that i think), but other provinces haVE decided to interprete the code differently. With a bunch of groups lobbying for legalization in ontario, the prov. government finally decided to give a green light once they realized how much money they can make off it.
Thats my understanding of it anyway.