Holly doesn't have enough power for Nunes to respect. Nunes doesn't rush straight forward at her opponents like Ronda, and she has good kicks as well s being more explosive than Holly, and her weak sauce punches.
Besides, shed just take Holly down, and tap her out within seconds. She's even more athletic and explosive than Holly, and is very well rounded. Ronda has no chance agaisnt her. Shed crack her once, and shed be hesitant the whole fight. A hesitant Ronda is a useless Ronda, and after the Holly massacre, I don't think she'll ever be the same.
Just based on Ronda's reaction after the Holly fight, not wanting to fight right away, being closed off, no words of, I'm gonna kill her in the rematch, just generally seeming like her hearts not in it anymore, makes me believe she has a front runners mentality, and when the going gets tough, she isn't the samr Uber confident fighter she once was. Her psyche is fragile, and she doesn't have a champions heart. Shes not built like that, IMO.
If any other fighter reacted the same way as Ronda after losing, they'd be called fake fighters, but of course, she gets a pass, because she's a girl, which is ironic, since they marketed her like she's above all the females, and on the mens level.
Look at Conor, and how he wants to Nate again, and avenge his loss. That's the mentality of a champion, win or lose.