This is a part of reasoning I don't understand.

"We would like for you to stop drinking Coca-Cola (IPv4) and instead drink water (IPv6). Here, have some more Coca-Cola."

How is that an incentive for drinking water?

It's not. It's an incentive for _continuing_ drinking Coca-Cola, because hey, maybe the nice fools will give you more Coca-Cola also the next time you run out.