And who had Nunez beaten? When you are a nobody and lose to another nobody, your name doesn't exactly go back to the top of the list. You can bash Correia and Holm all you want, but they had better cases than Nunez at the time.
As for Cyborg, as i've said about a dozen times, she was a steroid cheat and Rousey didn't want to fight her at 145. And since you like making the "who beat who" arguments, what great fighter did cyborg beat? She was mostly sqaushing smaller women.
Who is the nobody that she lost to?
I think you largely don't understand the flawed ranking system, though better than nothing in some regards.
Rousey didn't want to fight her at 145 because she was scared. She didn't even want to fight her at 140 or 135. Period, she has always been afraid of Cyborg.
Cyborg has beaten Holly Holm, Marloes Coenen twice, Gina Carano, but more to the point she has beaten everyone and hasn't run from people and she has knocked them the hell out.
Again, please look at the knockout success rate of the fighters that Rousey lost to and the ones that she beat and tell me there isn't a striking (no pun intended) difference. And the fight that everyone wanted and that would have made tons of money, Rousey refused with Cyborg, who also has a knockout percentage that is extremely high.
There is no way of ignoring it. She was a really good grappler, who fought people who were specifically less experienced at grappling with her, who had no real likelihood of knocking her out.
She finally faced someone who could knock her out, and what happened? She got knocked out. She faced another person who could knock her out, and what happened? She got knocked out even worse...
There are a slew of fighters out there who have well-rounded games right now. She doesn't stand a chance against any of them and she knows it, which is again why she retired.
She can't stay #1 forever and keep getting title fights loss after loss, so she would end up fighting some of these "no names" as you called them, who finally were able to climb the ranks by beating the media's named fighters, that were only known because they fought Rousey.
You look at the fighters that Rousey fought and you can see a distinct trend that largely none of them aside from Tate are accomplished. The next best was Zingano who just had a terrible fight against her.
You make your name fighting nobodies, and ducking anyone who actually threatens you, and people like you eat it up.