How successful do you think an evil 'Mr. McMahon' character would have been if they had gone with it in 1993 (when Vince did the Memphis angle playing basically the same character five years early)?
Without Steve Austin to act as a foil, it would have flopped. The magic was Austin's everyman character beating up Vince's universal boss character. Vince playing another cartoon character in 93 would have been terrible if opposed by, say, bland Lex Luger, who literally no one wanted to be.