In theory it sounds like a good idea, but unless a lot of things are changed or fixed within the broken system, kids with problems will leave anyway.
If this is going to work, they need to have comphrehensive means to assess what problems the students are having (boredom, learning disabilities, being bullied, having parents who don’t care, attitude problems with authority etc.) Once the problems are figured out, then these kids would/should be funneled into appropriate courses or programs where they are able to get the help that they need.
I don’t think it’s right to keep disruptive kids in regular classrooms, but just sending them to detention isn’t going to help. They need to be sent to a class or a program that is separate from the rest of the students, whether it is a program with intensive tutoring, or counseling for troubled kids, or whatever it is that they need. And it would be helpful if there were other options such as going to a trade school or other job training program, or even some type of community service type of program. The main part should be to actually help the kids, but in some cases, the point should be to keep disruptive kids off the street and out of trouble (that may sound like a prison, but if they don’t get sorted out, that’s where they will ultimately end up any way).
And the parents need to be held accountable for making sure that their kids don’t cause trouble for those students who want to learn. But anyone who has ever been a teacher, or who has any teachers in their family know that all too often now, lazy or belligerent parents often blame and threaten the teacher when in reality, the parent spoiled their child and let them mouth off, or be lazy and not do the required work, or the parents demand special treatment, “Because my child is a genius and we have money and political influence and we deserve special treatment.” Or the opposite, the parents are lazy and simply don’t care and don’t do anything to help their child (or the school or the teacher) to make sure that their child does the work and learns. There are a lot of stupid people who have children.
When they turn 18 and decide to be disruptive they can go to jail if they want to, but before that, it’s up to the parents and the schools and even government to protect them and help them, because they are still considered minors.
But none of this will be successful unless there are major changes to business as usual. Unfortunately there is no money, an no consensus to make these changes.