Once any place of business has a reputation of ‘that’s where all those fights happen’, it’s hard to get rid of that smear.
My guess is somebody who find them self in the mood to deliver a ‘knuckle sandwich to the mouth’ to the next person that tees them off, will head to a restaurant with that local reputation.
The popular belief may be “The staff don’t mind if you get a little rowdy there. They can deal with it.
People expect to see it, especially on weekend nights.”
I.e. Greens Point Mall in Houston is now known as Guns Point Mall