To clarify - given that this became a business relationship once they set up a Patreon account, none of that excuses their behavior.I get that , but there is a major difference here , those case of drifting apart don't involve money and any responsibility . At least usually .
I understand fear , anxiety and shame from having let things fester , and not keeping touch , and it snowballing . However this involves money . I can empathize to someone's struggle over this ... but there is a limit . Like the good Major said , somehow , there is no such hangs up about still taking the money , while being gone , for many devs in that situation . Again ultimately it is also and foremost a matter of respect for the people that did support them .
However, I'm not sure how Patreon payments are handled. I can't say for sure that all devs in this sort of situation take in the money actively. If it auto transfers to an account, that requires no action to receive the money, but requires action to stop receiving it (and what I've laid out implies a paralysis that could prevent action). I believe that on itch.io, you have to log in and withdraw the money your project has earned; a dev truly paralyzed into inaction presumably wouldn't withdraw that money (although itch payments are a one-time thing, not an on-going financial relationship).
Turning off Patreon payments for a while would be appropriate in many if not all cases - but requires taking action, presuming including some sort of message to indicate that they aren't actively working on things now.
Note that subbing on Patreon is agreeing to send money to a person, not for a project. Many devs set up rewards for various support levelsb however, i dont necessarily believe Patreon requires them to make good on the rewards promised. I didn't see language like I saw when I participated on Kickstarter recently; they explicitly say that the various rewards promised for support are not Kickstarter's responsibility and aren't enforced by Kickstarter in any way. My assumption has always been that Patreon is operating on the same principles; you decide to give Joe Shmoe money, and he has no actual obligation to do squat about it.
Again - once the dev makes it a business relationship by setting up on Patreon, it is rude and unethical (in my opinion) to keep taking money if whatever you promised isn't being delivered. There's only one thing supporters can do about, and that's choosing to stop their support.