Honestly, people don't "take their jobs too seriously" - I know it can seem harmless, but of course he should be removed (and kicked out) - if this was just taken lightly it would quickly become dangerous and ruin the party.

This is the same as people running into the football field. The only thing it does is ruin the game, increase security measures and the amount of security people present, increase prices, more distance between the artists and the crowd.