I'm not saying women's MMA wasn't a thing. Clearly it was. Just that Gina's potential appeal meant that broadcasters like CBS and Showtime were willing to take a chance on her and therefore women's MMA in general.
When Gina fought on CBS the ratings went up, when her fight ended they went back down. It's something that promoters and broadcasters notice and look to build on. That's why Strikeforce main evented with her. That show was a huge breakthrough moment for women's MMA and the promotional appeal came from Carano, not Cyborg. After all, with
the EliteXC show on CBS, Gina was on the main card on network TV and Cyborg was on the unaired prelims despite Cyborg's fight being for that division's title.
This isn't about how good a fighter she was or wasn't. It's about the appeal she had and how that grew the women's divisions as a result. She was a huge part of the reason Elite XC and Strikeforce pushed their women's divisions.
Yeh Valentina Shevchenko and Amanda Nunez are clearly better fighters than Gina ever was. But how big were the shows they were fighting on before Gina was a thing? Not exactly on a CBS or Showtime level. were they? In the timeline of women's MMA there's before Gina Carano and after Gina Carano. It took a step up because of her and then took another because of Ronda Rousey.
Bethe Correia, Holly Holm and Joanna Jędrzejczyk hadn't fought in MMA before Gina's fights.
Ronda might not have gotten into MMA if Strikeforce weren't showcasing its women's divisions and therefore creating a path to a decent career rather than just small regional shows. Her having medalled in Judo was no guarantee she would then move to MMA.
Also, people were speculating on Gina returning to MMA for years after her retirement.