I give respect to Rousey for mentioning her father often after a fight (who committed suicide when she was young), most women won't acknowledge their father even if he is alive, and for that I credit to her. This was the reason she was pissed when Correira told her "you are going to kill yourself" before the fight.
But beside that, well she is a good fighter.......for a woman, the media loves, she gets attention, that attention makes bring more sponsors, plus, and this a big one, Rousey has a big ego and entitle personality when talking, she has this bitch resting face, so, many women who don't even care about MMA can identify with her.
Like many have said, people and Rousey herself were hating on Holm because she has a more feminine persona.
You have a girl from Riverside California that has been all over the media who just a week ago endorse Berny Sanders, VS, a girl from Sandia Heights New Mexico, Midwest, the only thing missing now is Holm endorsing Trump.