Parents banned wholesale from school event- UK

It's not specific unruly or dangerous parents discussed in this article. It's all the parents. They've asked parents not to attend Sports Day (what we in this area know as Field Day, i guess), so as to minimize the stress of being watched by a large crowd. Apparently, the concern is that the kids can't enjoy themselves if their parents and the parents of their classmates are around. Uh, excuse me? What kids doesn't want to perform, or even show off, for parents? And those that don't care to participate shouldn't be required to. Simple. I'm with the parents who want to boycott and organize their own event.