Most of those same people complain every day about Marvel's treatment of X-Men in comics and the general direction they have gone in with their media so I highly doubt x-men in mcu will really equal more happy people. For a company that has shied away from dark stories they do own rights to like Demon in a Bottle, made Guardians of the Galaxy into essentially kiddie merchandising generators and have erased darker aspects of something like Civil War, I doubt Disney will give people the X-Men they think they will give. It's all about corporate image and branding, and the mutants and their heavy themes clash with Disney's MO.