We live in a world where if the cost of too high for something like this, it will be written off as unnecessary. Unless there is someone really pushing this from within, Facebook/Instagram/etc probably won't implement something like this, or will just create their own (possibly poor) substitute.

I get the idea that people should be paid for their work, and it's his choice how he licenses it. On there other hand, if the point is to make sure this spreads as far as possible and gets used everywhere, then maybe a very permissive license is called for.