The obvious solution would be to allow schools to expel and get rid of the warehoused students. (I don't expect to see it happen however.)
I don't want to see it happen either. These same "students" become citizens and neighbors at one time or another with rights, votes, automobiles, et al. I think that we (as a society) should expend as much effort as possible to attempt to educate them. If we don't, we end up paying for them in prison/jail, rehab, welfare, et al. I haven't seen a decent cost/benefit analysis, but I would intuitively believe that it is cheaper to try to keep them in the system than have to deal with them after they've been expelled. My $.02.