There's a different mindset among the very top competitors. Legendary wrestler Dan Gable only lost one match in his entire career - but that one loss made him so upset that he was too ashamed to talk to his parents for weeks. I don't think that sort of outlook is emotionally healthy, but it's part of what gets those people to where they are. I don't have a hard time imagining that Rousey was upset at missing the gold even though a normal person would be thrilled just to qualify for the Olympics, let alone earn a medal.
I don't get what that has to do with the OP being disgusted at the UFC or MMA, though. It's just a background story about how she felt when she was doing judo, before she even thought about getting into MMA.