Full of tuitioned kids with rich parents and kids from private primary who are tutored to pass the exam.
I don't know what some people think tutoring is. It's not force-feeding 11+ papers to hapless children for hours on end. In my case (and I'm certainly not rich), it was a means of getting my 3dc to focus for an hour a week and have some practice. It would have been a frustrating, stressful business to try and get them to do it at home without the particular discipline which a tutor can bring. It wasn't at all intensive - during Yr5 (term-time) they all went for 1 hour a week to a tutor who held sessions with groups of 6 - 8 children, and I was lucky if mine managed to do 1 paper in between sessions!
It's the biggest myth that you can tutor a child to pass the 11+. This was sadly demonstrated by some of the children in last night's programme. What tutoring (or practicing at home, if your dc will co-operate) does do, is to give a child the confidence of walking into the exam room knowing they're not going to be faced with anything they haven't encountered before.
State Primaries have, in most cases, opted out of giving 11+ practice, so a lot of parents enlist the help of a tutor, because they don't have the confidence that they can 'tutor' their dcs themselves. Name me any other exam/test which your dc would take without having had any proper practice? As mentioned above, Private Primaries are fully geared up to giving 11+ practice at school. My state-educated dc and their peers, unfortunate enough to have an excellent Grammar vs. under-performing alternative schools, were left to their own devices, so I am not going to be ashamed that I paid £15 a week for group tuition, to save myself the angst of trying to corral my dc at home!