They trash him because Doffy's entire arsenal is a bunch of plot convenient devices that make him objectively impossible to powerscale no matter what some people here try to argue. Parasite was already bad, but Bird Cage takes the cake as the most imbecile ability in One Piece.
This chapter is a perfect example of how not to take polls too seriously. The vast majority of OP fans are casuals tbh. If you made a poll King and Queen vs Aramaki i can assure you the Admiral would've lost but here he trashed them in the manga.
Of course he would! Only because there is one delusional guy putting the "Doffy = Low Admiral Level" narrative consistently, doesn't mean that Doflamingo is even relevant to the likes of Admirals. He was at Aokiji's mercy, thankfully it wasn't Greenbull who found out about his piracy in Dressrosa.