Yes, I'm sure the organisers could try sanitise the event - nobody may exceed Zmph or ride in groups of more than 4 people - but that's not easy to police and more often than not, it's unjustified...
Is it unjustified? All I read for months ahead of (and after) RL100 is people complaining about those morons whizzing by at 30 mph and scaring the hell out of people and how these people cause crashes.
Surely if you put a deterrent in place and it's well advertised, they will refrain from entering. It's the message you send out, whether that deterrent actually works on the day might be immaterial.
You apply a zero tolerance policy on bad behaviour or you don't... if you don't then don't complain if the BBC calls it a race, because at the front that's exactly what it is