If you're part of the crowd, would you let them through? I go to watch the London Marathon every year with friends. We usually have a number of people we know running.
The day is planned so we have a spot where public transport works quite well for us and loos are nearby. It's a spot that doesn't get as busy as some of the more popular spectator places, but it can be 3 for 4 deep at peak times.
We get there early and stay all day to secure our spot on the barrier. It's a long tiring day, which might sound ridiculous if you've never done it, but it is and you have to concentrate hard to spot your friends amongst the runners.
Having secured the spot no one is keen to give it up to let children through to the front. You might be able to see over their heads at runner directly in front of you, but you really need to be able to lean to see runners coming.
Last year, for the first time we had lots of persistent children asking to be allowed through. They didn't ask once, but kept on and on while parents tutted that the crowd didn't open.
Now, I know people will say what a fuss over nothing, but this important enough to those involved that they get up early and stand in a crowd all day, whatever the weather. If you can't imagine caring that much, think about something you do care about.
Is it reasonable for the parents to let DC keep asking and is it reasonable for spectators not to let them through?
Or is it reasonable to expect people who want a place at the front to get there early enough to secure it?