I know this topic has come up in the thread before, and I agree with you, it seems like people have a pretty distorted idea of how hard it is to create adult content for pay, and will go to great lengths to justify their accessing it for free. With that said, it does cut both ways. There's a substantial portion of folks who will buy if they get to try first, and especially in adult-content creation, income tends to be disproportionately contributed by 'whales' who provide very much more than the minimum contributors. This is true across patreon, but its especially true with adult content, where people who find something that hits on their particular fetishes and have substantial disposable income may pledge hundreds a month to ensure it continues to exist. This pattern exists outside of adult content (it's how many F2P/P2W mobile games work), but its especially amplified in adult content.
A lot of 'legitimate' paths to income are not really available to adult content; DPC has his material on Steam, but it's pretty uncommon to find XXX content there and there's more topics that aren't permissible. Criticizing the creator for using the best tools available to them, even if those tools are inadequtae or flawed, is pretty silly.