Yes it is taught to children because of the achilles' heel, but there are a lot of people that do know about the Trojan war, and myths associated in which Achilles played a major role with a lot of other drama going on. the heel had to do with his death, just one part of his story as a hero. Again if you look at the most popular representation of him in recent memory, the movie Troy, the heel was barely mentioned and just at the end.