Yes they could. Or they could just boo and tell what they're thinking as well. Just because they may hate a lot of the show, doesn't mean they hate all of it. Plus the average wrestling fan sees WWE as the only wrestling entity. They're the biggest promotion and average fans see WWE as the only real product. I mean that's quite obvious or they wouldn't be so big
And to continue to give them money and ratings isn't going to encourage them to make the changes people want. WWE is a business, if people will still pay then as far as they're concerned they're really not obligated to do anything the fans want.