[0zymandiass]

They don't want to support charities. They want to get people that want that to spend more money with them. They did the math, and the number of people that will say "no" to that permission is significantly smaller than the amount of money they make from forcing that permission in order to get them to give their scraps to charities.

[CydeWeys]

Even better, they want cheap advertising from charities. Plenty of charities broadcast to their network that you should go set up Amazon Smile to support that charity. And thus you get charities advertising for Amazon.