Deadpool is funnier, basically. When it comes to violence in media, funnier is always more 'acceptable' because it seems less real, and more like a cartoon. And Deadpool's never done bad stuff to her before (like kidnap her and lock her in a cave) they also didn't have bad power dynamic, Deadpool wasn't the her 'boss' nor was he supposed to be more powerful. Whereas mags is always more powerful and always in charge in some way. In legacy he was 'Vice President of uptopia and in AoA he was literal her boss/teacher/foster father. I still don't like Rogue/Deadpool because if it ever did go anywhere, she'd have to give up all of her moral/philosophy ideals to stay with him, which is not good, and he'd be an incredibly annoying boyfriend. But most people still find annoying boyfriends more acceptable than domonieering and frankly, abusive boyfriends.