I am disgusted by such "sports". I will not watch them or follow them in any way. I noticed that events like the Olympics have started showcasing these sports and they are becoming more prevalent on television sporting broadcasts which reduces my likelihood of viewing television sports.
I would tend to believe the post above which says that most of the fans of such activities are men. For reasons beyond my understanding, most men always loved watching cat-fights, women's mud wrestling, etc. I presume it is because most of the time women are doing these types of activities, they are scantily clothed or wearing very tight clothes, and men's lusts are energized.