That's unfair to Stanton, he only made Dory after John Carter, and Pixar Animation takes forever to make, it's not like he could go around and make another live action film for Disney anyway, whatever the response to Carter was.
And Whedon made the two highest grossing films in the MCU, whatever expectations were, that is still a reason not to kick him to the curb. Whedon very publically admitted to be worn out by big blockbusters and has gone back to comics for the time being.
And Edgar Wright is an asshole who deserved getting his ass booted out.