Actually parents, grandparents, uncles and aunts of girls who play soccer (and there are far more of them than the number of people who fight or even watch MMA) care about female soccer. I'm in that category -- a grand daughter who plays. She knows the names of some women's soccer stars, so I know their names too now. And I've even watched some women's soccer games with her.
Don't underestimate the power of children to get their parents and grandparents interested in what they're doing -- there's huge money in spending on children's interest ... and more, anything that gets your kids / grand kids off their butts and active is looked at very fondly by most parents/grandparents.
Which is why ESPN shows women's soccer. The disposal income of MMA fans is minuscule compared to the disposable income of parents around the world who have girls playing soccer.