Good points. I think a lot of people on here bring up good points. I do think though that there are a bit more men and even some younger generations turned on by a catfight. Yet there are things to consider.
I do think the point a lot of people are making about how violent the fight does matter. If this is a battle where there may be a few rules in play then that may be more acceptable then two wildcats going all out.
I do also think that the attire and the possibility of said attire getting ruined also plays a factor, even if the women going at it are fighting (no-making out) the fact that they might be topless or nude while doing still does add to the enjoyment for the men watching.
Now I do think that the popularity of catfighting has seen it's ups and downs, You did get some entertainment from the old Betty Page movies back in the day, and had some good video companies come up when VHS was a thing, some even stayed till the advent of the DVD. I do think as the internet became popular, and sites began showing videos for free that a lot of places got looked at. Yet even though those sites and videos were popular that didn't exactly mean that they were in the public eye as much though.
Yes this isn't exactly an easy topic to bring up in a conversation for men, no matter if they are talking to a man or woman since as some have pointed out on here Catfighting is a bit of a fetish that I do think a lot of people may have, yet not a lot are comfortable sharing, since the fact that it is a bit of a fetish and therefor a little bit out of the "ordinary".
I do think though that there are a lot more men who keep this fetish a secrete even though it may leave some of their deepest fantasies unfulfilled (Having a match with a female themselves or having a "ring side seat" to a match involving two or more women) which I think can be hard for some.