My older daughter was very anxious about detentions, even though she never had one. She did feel that it would be humiliating for others to know she had broken the rules (she is my Lawful Good child, who is now a TA apprentice who has overseen primary school children who are held back from break and has chilled out quite a bit by her own admission).
My younger daughter doesn't care, and has had a few. She just uses them to do homework before going on to another afterschool club or home. I was like that - it wasn't a loss of freedom, for me it was freedom in the quiet. It was never humiliating - why would I be humiliated to sit quietly in a room like that wasn't what I did most of the time? I get it if a teacher or the school was to publicly shame them, which I've seen but is not often the case.
*But if you've ever attended adult classes, can you recall being punished for being late? Or for not completing your homework?
Yes, I attended a community college in the US where not attending prevents people from participating in sports and other clubs on campus, and can result in more severe consequences including having a low attendance marked on the transcript that follows after leaving. Any job that asks for my pre-UK qualifications can see them.
In the UK my son, who is 20, attends adult education where he is not allowed to be in his room from 9am to 4pm during the week unless he is ill and has followed reporting procedures which involves contacting his course tutor and training provider, and he must ask permission to be absent for any other reason. There are punishments for being late or absent without permission and after the 6th absences without permission, he would get kicked out, much as other gross misconduct like failing one of the random drug test.
He is technically free to leave as he was at secondary, but unlike then, it would cost him - he has a sponsored place and a contract that if he leaves or gets kicked out, he has to pay thousands back - a not uncommon feature if you can get a company to pay for your adult learning. This is the child who chose to be home educated until he was 15 - yes, some kids do get that choice, all my kids when they chose to enter secondary were shown and discussed the behaviour policy, uniform, all the rest. I'm not a parent who argues with a school about the rules we could read and ask them about beforehand. I find that respectful both to the school and my kids. I have chats with my younger daughter regularly - you can make the choice if you're willing to deal with the consequence.
Children in happy families do not sit in the lobby.
Oh dear, that's an interesting assumption, especially when it comes to kids who fall in line with their friends. I find Year 7s particularly vulnerable to this as they adjust.
I'm a governor at a school that has a lot of 'corridor wanderers' (though when I was there in the summer, there were a few wanderers Naruto racing down the hall). Schools are being really pressed to deal with attendance, including internal truancy, it's a safeguarding issue so now they all get moved into a room to study, which can be viewed as a school time detention or a natural consequence to keep them supervised and the classes undisturbed. Some of the kids are from happy families, they may also hate a particular teacher or find the quiet room studying on their own more appealing than a busy class or prefer being with their friends even when they can't talk. Near everything about schools is out of a child's hands and restrict freedom if we want to view it that way - detentions are the least of it - so yes, some push back sometimes because they feel safe enough to do so.