I don't think most people use them for the whole holiday though? Not the summer one anyway 6 x 5 days. We've never done all days all holiday, usually 3 days at each half term, Xmas and Easter. She's doing 6 weeks of 3 days this summer, which still leaves plenty of time for some family days out, downtime at home and playing at the local park.
My Mum tries to guilt trip me each holiday, makes it sound like I'm sending DD up chimneys or down the mines! But DD really enjoys it - we showed her the activity list and she helped choose which days she wants to go.
I did stay at home during holidays almost all the time as a kid - we'd visit some deadly boring elderly relatives every week (have to sit silently and not interrupt) have a week's family holiday and otherwise spend the whole time reading and arguing with my brother. I think DD gets a much better set up!