[ptaipale]

The counter-argument to that is that kids take a lower track than they could well handle, if they have talent but are a bit lazy, or come from disadvantaged backgrounds (socioeconomic class where parents have no academic ambition, or perhaps no interest in their kids' school at all). This is not entirely rubbish, although I do think that some different tracks would be a good idea.

When I went to school, there were e.g. three different levels of maths in junior high here; with my kids, everyone in the age class followed the same curriculum in maths, languages etc. This leads to a differentiation of schools - since you can't select more ambitious classes within one school, parents try to get their children to elite schools where the academic level is higher and there are fewer distracting "students".