LeQ, surely the point is that although thousands of children are indeed talented at, for example, art, it will only be those who have access to better pencils and access to particular cultural capital who go to art college.
The education system does indeed wait until post-16 in fact to decide whether they genuinely have a 'flair' - that's why there's some attempt at a broad base for all until 16 (I'm aware that this is being eroded by the excessive use of vocational qualifications), and specialising via 'A' levels.
The issue is primarily one of opportunity and expectations, not giftedness. Otherwise, everyone who didn't go to art college would be rubbish at art and that's obviously not true.