No "illegal" guns...
When I see a "no guns or weapons" sign(s) in a private business, I assume it's for illegal or unlawful carry of concealed weapons.
If you have a concealed weapon or a valid carry license, I wouldn't worry about it. If they see or spot your sidearm(or folder knife), just pay your bill & leave.
Most servers, managers & waitresses are far to busy to stop and stare at customers. If you are a "quiet professional" & are a mature adult, you should be okay.
I wouldn't pack heat in a bar or nightclub anyway. If you carry, do not drink either. It may be legal but you'll face a lot of problems over it if you draw a loaded firearm in public.
I agree with the other forum members too, you could just avoid spending $ in a business that does not support CC license holders or the 2A.