I understand your point, but I still think it is worthwhile advice. This trick saved me very recently when it was clear that a driver had not seen me (and my 4yo!) on my bike. I was able to start braking hard even before she pulled out and thus avoid the collision. So, while you are correct that just because someone looks at you, it doesn't mean they see you, it is also true that if someone doesn't look at you, it means they almost certainly didn't see you.