When pressed, most of the justification for RP beliefs rests on a collection of anecdotal evidence from the manosphere. It's a bunch of guys comparing notes on their experiences with women and then using this information to generalize certain traits about women as a whole. There is a fundamental problem with this though, which I will illustrate with an example.

How many women know a guy who quickly changed from nice and friendly to a vindictive asshole the moment he realized he wasn't going to get his way (get laid)?

I think most women can think of one or two guys who have behaved this way.

Perhaps even the majority of men have behaved this way at some point in their lives.

Would it be fair to say that men in general turn into brats the moment they don't get what they want?

No. No one acts perfect all the time. If you look at any person long enough, you are going to find a specific instance where they were selfish, immature, illogical, vindictive, arrogant, entitled, or manipulative.

However, if you look at any person long enough you will also find specific instances where they were unselfish, mature, logical, forgiving, humble, generous, and altruistic.

That is just the way most humans are. Perfectly good or perfectly bad people are very rare. Most people have a mixture of both good and bad traits.

So if we are going to look at specific instances, then we could just as easily come to the conclusion that women are altruistic rather than women are selfish. It just depends on which behaviors we select for consideration.

If you want to be logical about it, you would have to look at the behavior of most women or the behavior that women choose most of the time. But TRP doesn't do this. They look at behavior that actually only applies to a minority of women, and then generalize this behavior to all women.

To give a concrete example, TRP will say that women love bad boys and use the fact that some women date convicts as an example. But how many women actually date convicts that aren't engaged in illegal activities themselves? Not very many. Instead, women tend to date someone from their own social class. Wealthy women date wealthy men. Lower class women date lower class men. This actually represents 'female behavior' better than what TRP says, because it actually reflects the majority of women rather than a minority.

You could say that most every women has an asshole boyfriend story. Well yeah, but every man also has a bitchy girlfriend story. The mistake TRP makes is confusing the probability that person A has done X at some point with person A will do X as a rule. It's like if you roll a dice enough times, the probability that you get a 6 is pretty high. However, the probability that you will roll a 6 every time, most of the time, or even the next time is low.