True, a helmet is better in all kinds of ways. It doesn't need a battery, it still works even when things hit you rather than you hitting things, and it's an order of magnitude cheaper to replace after a knock.

But if someone will wear one of these things who wouldn't otherwise wear anything at all...

Cycle routes in the Netherlands are awesome! Things are slowly improving here, but we're still a long way from that level of care placed into the design.