Well of course not, because schools don't have the support they need to help those students in turn.
>>goes to work at macdonalds
I don't know where you live where employing 15 year olds is legal, but even if we assume some kind of state where it's allowed, what mcdolands would employ a 15 year old that was expelled from school?
>>and comes back later,
How would that even work? You mean they enroll back at a private school to get their education? With what money?
The path isn't "well they get expelled so they just go to work" - most likely the path is that they just stay at home doing nothing all day if their parents let them, or they just turn to vagrancy/crime. No 15 year old is going to go "well I got kicked out of school so I better look for the most basic job" - it's some kind of unrealistic pipe dream of how society works.
But either way - you haven't really answered my question. In most places a child has to be in education until they turn 18. So when you kicked them out of school at 15, what is the state supposed to do with them?
I mean the money that government wastes keeping them in school while they are 15 and don't want to learn, can be given to them later when/if they decide to learn.
> most likely the path is that they just stay at home doing nothing all day if their parents let them.
That's up to the parent to decide: leave them at home, convince them to find a job, go to special school or a class for misbehaving children, go to trade school etc.
Those who turn to vagrancy/crime do it anyway, as they have enough time outside of school too.
> child has to be in education until they turn 18.
> employing 15 year olds is [not] legal
These are not physical laws given to us from above, these are rather misguided attempts by politicians to look good, and are harmful to the society.
Imagine that instead of prisons we were forcing criminals to go spend time sitting in offices and disrupting normal work. What we do with children now is equally effective.
> So when you kicked them out of school at 15, what is the state supposed to do with them?
The threat of such should help encourage parents to actually raise decent children.