Similar to manic insomniac.
I get a good break on tuition fees, and don't pay for childcare. So right now dd is in the library doing homework, I am on mn and thinking about going to TJ Maxx for half an hour then picking her up!
Dd needs some extra parental input and there is no way I could do this if she was in a different school.
Currently she's in the equivalent of elementary, but from Sep will be in middle school with me and I will be teaching her every day once she's in 8th grade.
The plus side for me is the huge convenience of not having extra drop off and pick up times, I do get time to see her special things, if I want I can drop in and see how things are going (not often), I know who people are and what is going on.
The negatives - yes, our entire lives revolve around one place, dd's clubs are all based here etc, it's inconvenient if I don't agree with her teacher and we have to resolve something, everyone knows who I am etc.
BUT I love this school and want dd here so it works OK for now.
I think the difference can be in whether the parent has ended up in the same school as the child because there are good reasons to be in that school for both of them, or whether the parent just wants to be there to be near their child and can't separate themselves from their parental role.
Until this school, we were always in separate places, but 3 years ago I got a job at a great place, and once I was secure there I applied for dd to be in the school as I could see how much it would help her.