> By the same logic, I should be able to walk into a store and just take anything I want because I'm using it to make items I sell "for donations". Obviously, that's ridiculous.

HN's favorite pastime, using terribly inappropriate analogies for things they don't understand. Because taking actual, physical items (also known as theft) is the same thing as not using Google's paid for service to receive tips.

1/ Developers already pay for access to the Play Store. A minimal fee, sure, but if Google wants to make more money, then they are fully free to raise that.

2/ You are not using their service to process the payment. Google forces themselves into the process simply to extract 30% while doing absolutely nothing.