Of course there are fans of other teams that hate the Browns, especially from the same division. this is a silly discussion.
Hell, we hated the shit out of the Dubs from 2014/2015 onward, we hated the Pistons back in the day, we hated the Wizards, the Bulls, the Celtics, you name it.
Anything that threatens the status and success of your team or in any way looks to upset the status quo to the detriment of a team, however realistic the prospects of that may be, is bound to get hated on by a some part of the fanbase.
This is nothing new, except for the fact that it’s happening to the Browns.