#2 It is best for business
Very soon Brock Lesnar will presumably be leaving WWE, and the company will be in the market for a new menacing heel who disrespects fans and taunts opponents. Ronda Rousey can seamlessly slide into this very same role.
Imagining all the ruthless aggression Ronda can inflict on her opponents is euphoric. She can do any number of things from blatant chokes to scraping eyes, to delivering cheap shots or using weapons. Ronda can even attack people backstage or interfere in other matches for the fun of it. The new Ronda Rousey would be so arrogant and cocky the WWE Universe would have no choice but to relentlessly boo her.
A top AEW star just called one of his colleagues 'spoiled' and 'narcissistic' HERE.
All in all, Ronda becoming a heel will be what is best for business. Giving Rousey a fresh direction while opening exciting new opportunities for the women's division.