I thought it was all to do with this public liability insurance with events with more than ??? present.
Stopped a heap of country fairs and Highland Games up North. You were talking a tenner a head just to stand in a cow park because of some public gathering Law. The fact the event had run for the last 60 years and apart from the odd punch up between the young farmers (they were all still up to feed the beasts the next day) no one was ever hurt.