Ronda has virtually no way of beating a fit former boxer, especially one who can kick well. Holly killed her in the punching exchange and just kept kicking and attacking whenever Ronda attempted to try and take her down
even when Rousey DID manage to get Holly down for a moment she lacked the strength to keep her there
this is an impossible fight for Rousey to win. I will add that Holly has a pretty big previous career in boxing, she was great, so it's not THAT big of a shock.
I think there are plenty of contendors that would destroy Ronda in a fight if given the chance, it's just (obviously) that the UFC wanted to cash in on her hype and put up certain fighters (notice her opponents generally had limited experience, limited reach, not bulky, limited boxing experience, etc.)
congratz to Holly though, watching her interviews before and after she's such a gracious person
