Midchuck,
I hear what you are saying, and to a point agree,
I try and occupy them if I suspect they may find things a little tedious - my kids have a festival bag, in it is paper, pens, books etc, things to keep my kids quiet, and in the main, it works, many parents have complimented me on a) the good behaviour of my kids and b) the wonderful idea that keeps them so quiet. Perhaps festival organisers could have a box of pens and paper for kids to play with at venues.
As performers ourselves, our kids have been brought up to know that they have to keep quiet when people are performing, and in the main are good, I too have experienced being in a concert with the child from hell 2 rows in front and sympathise with what you are saying, but believe me, I really do think twice about taking my kids into a concert if I have not paid for them, paying for them makes me want to take them, otherwise, I am paying for them not to be there - and me not to be there either, because if they can't come in, neither can I! If a child ticket, for example, and I quote from a booking form, is Under 15 year olds and pensioners half price..... I am paying three times for not going to what the pensioner is paying once to really enjoy - now whats fair in that?

Sharon, prices differ from festival to festival, some have under 5s free, some, like Miskin last weekend, kids were free, some are half the price of adult tickets. There is no hard and fast rule.
And I really do feel like I am subsidising the childless, LOL if you like, I personally dont find it that funny!
I'm not trying to be antagonistic, just soapboxing again!

My eldest daughter is eleven, and because we have dragged her to festivals since birth, and she has a lovely singing voice, she is now singing traditional songs with us at singarounds etc, Our youngest is 7 and has been playing the fiddle for 14 months - her choice, not ours.
Its the 'Kids half price' one that got me, with not a single thing in the programme for kids - Hmmmmm.
Leaves a lot to be desired really!
Cheers, Lucy