He didn't "go" boring and vanilla, it's that the times have changed.
Content that used to be controversial, like dicks on girls, piercings, center-of-attention assholes, explicit lolis, is now considered trite and common.
Shad built his entire identity on being controversial and edgy, so he's desperately trying to keep this train rolling by doing edgy meme comics. But he's becoming less and less relevant.
His haters are not the strongest source of popularity he has.