I don't think the fighting itself turns most.men on, I've yet to see a picture thread of men posting pics of female MMA fightera mid awing....
I think its a combination of an expectation of two women that look a certain way not being able to really fight, and the benevolent attiude we'd express towards say kittens or puppies fighting...i mean of your repertoire only consists of open hand slaps, unskilled wrestling, tearing at clothes and pulling hair, then yeah the result ia probably going to be two unhurt, sweaty hot women with all or most of their clothes gone...that are hot and bothered