The problem with Bisch firing Cena or stripping him (of the title!) is that his character is subservient to Vince. Mcmahon Ex Machina can simply show up the following week and reverse the decision.

For Bisch (the character) to be truly effective, he must be seen to have real power over the show (like his character on Nitro) and not simply be seen as Vince's. . .bisch.

Y'know, things that WWE doesn't seem to understand anymore.