I think it's hard to judge - the mum who wanted her son to make friends, was that bad parenting? Because surely, if you have a child who is very bright and very socially awkward, and someone comes along to tell you there's this fun thing he can do where he'll meet other children who might not run away when he asks them about quantum physics, you might go for it?
I don't see a lot of sign that some of the children are bothered by it at all. I know some are, but others are bouncing up to the podium, answering and then going off and chatting to each other.
Don't get me wrong, I think British MENSA and C4 are being exploitative, narrow-minded tossers in this instance, but I don't think all the parents are doing something bad.
I'm not a parent and I never knew children as precocious as the brightest of these (though I did know children similar to the less bright ones), and I do think it must be hard for parents to know how to keep their children interested. Especially when, with Rubiyat's dad, he doesn't understand the maths his 11 year old son is doing!
On an earlier series of this programme, there was a mother who was a university lecturer and her son was very bright, so she'd sent him to learn Old Norse with a local Oxford don. Obviously, that must be nice, but realistically, how many people have that as an option?! And there must be a limit to how many times you can tell a child to stop being interested in something hard, and to go play outside, before it becomes actively cruel.