As someone who has promoted conventions before. Admission to a convention (of any time) is not permission to be verbally abusive to others. If some douche is calling people names and verbal abusing women, and you witness it, man up and ask the victim to come with you and you both find the convention organizer and everyone confront the guy. Then all sides are heard, witness, victim(s) and jerk.
Any decent convention organizer would then politely inform the jerk of what type of behavior is not allowed. Then if it happens again the jerk is shown the door with no admission refund. If he is a vendor same deal.
It is VERY simple.