In an "entertainment venue" I would totally agree, but the behaviour complained of was in a bar, open to the public for anyone to wander in.

Different ball game, different rules. There are pubs where the locals who drink there all year round do not appreciate a load of "dickheads" coming in once a year and taking the best seats and making a bloody racket with instruments and singing so loudly that you have to shout to be heard when using your mobile.

They have as much right as us to be there and to do what they normally do there. I find that goodwill and reasonableness is usually reciprocated - as is the opposite! Live and let live.