Joseph, chances are you are supposed to be dan lekaf zechus.
Notpashut, why CANT you go into a bar? If you are going to say its assur, you should quote a reason. I have no problem with anyone going out for an occasional beer with friends, so long as they are overage. Is there a halachic reason why they shouldnt? Then, that would be a different story.
You can just walk around saying “Thats wrong” without a reason.