I don't think high school relationships are bad as long as they don't interfere with the boys' and girls' education. After all, getting an education is the main reason we go to school. The socialization comes secondary. If high school boys and girls can keep their priorities straight, there's no reason why they can't (and shouldn't) have good, healthy relationships.
I guess what I'm saying is I don't really detest high school relationships unless they lead to the couple's downfall (teenage pregnancies, failing grades, poor job performance, problems at home). But, I don't exactly encourage them either, for the same reasons. However, if young people show they can be sensible, responsible, and mature in something (like dating), they should be allowed (even encouraged) to do it.