Yes Beauty and the Beast is a bad boy-good girl trope but it was a complete story played out in 2 hours. The problems I'm speaking of mainly applies to tv and books to a certain degree. I won't get into how far apart Disney's Beast is to Rumple on the badness scale since that's been covered by everyone else, but when that story is played out over 4 seasons? It's headed straight down towards the pits of idiocy as demonstrated by the fact that Rumbelle only worked well for one episode, Skin Deep. The 2 hour movie or 1 episode only really allows for one screwup or a 10 minute spat before the bad guy is fully and truly "reformed." Everyone's allowed 1 screwup. That's never going to happen in a long running series though.
Rumple is a character that should never be a love interest. There's plenty of other romantic leading men on this show for that. Now it seems like every single action of his is framed within the context of Rumbelle, which I think was Robert's point in an interview awhile back. I liked him with Cora but I thought their ending was perfect for them. If he has to be with someone, I much rather him be with someone like Ingrid. She doesn't take crap from him, is powerful in her own right, she's not power crazy so there's not that "bringing out the worst" in each other dynamic he had with Cora and she would be protective of Emma and therefore the good guys. That would be a better way to "leash" him than what they've done with Rumbelle. Ingrid would just thwart him instead of bleating about his good heart and she has the power to go toe to toe with him. Watching them try to outwit each other would be entertaining at least.