I'd definitely prefer dogs to be kept out of concerts, bars, food areas at festivals, as much for hygiene as for safety. A dog once jumped onto my lap and it hadn't cleaned its bum properly. Imagine that when you haven't got a change of clothes handy!
I hate the thought of dog hair, slobber, even poo, on my chair, clothes etc. Sorry if some people couldn't attend a festival without their dog, but it's not unusual for dogs to barred from public places.