I don't like the idea of thinking of, or labeling, kids as "bad". I think, though, that there are children who do better with more structure and less opportunity for (lack of a better way to describe it) for "freedom" to be a problem to other kids either within the class or during "free time" (recess, for example). Also, it makes a difference how old old the students in question are.
To me, regardless the type of approach used by the teachers/school, the youngest of kids need a certain amount of structure and (obviously) adequate and capable supervision as the framework within which the approach to "teaching style" needs to operate. As far as free time, like recess, goes; I don't think any good-sized group of kids does very well without adequate supervision keeping an eye on the goings on.
So, to me, with the youngest of students, I just think if a child has trouble "going with the program" but isn't a child who is routinely aggressive towards others, or who is not routinely disruptive in class (within the context of his/her age - that's obviously not a "bad" child. If there's a child who, on the other hand,is aggressive and unruly regularly then I pretty much think a) that "children's services" should be contacted in order to check into what, at home, is making a child be routinely aggressive/unruly so that the child's "issue" can be addressed. (Maybe the child just has the kind of parent who didn't know how to prepare him well for school and/or for having the kind of self-control needed not to be acting aggressively toward others. I'm not suggesting that the child be taken away from clueless parents - just that the parents/family could use some level-headed guidance.)
Schools for "bad kids"? No. Schools that know how to address the needs of routinely aggressive/out-of-control kids (without using aggression/lack of respect toward them)? Yes.