I knew I should have responded to this when I saw you mention this the first time (can't remember which thread, but that doesn't matter anyway). It's not about supporting a game, it's about supporting a dev. If you have only one good game in you, that's a shame, but milking that game so you wouldn't lose your patreon money will just tarnish that game. The whole idea behind being a game developper is that you develop more than one game. Of course, when the first one crashes and burns, you'll likely not make a second one, but that is the initial intention.
You say a developper isn't motivated by Patreon to finish games, so let me give you some examples of successful developpers who finished theirs: DrPinkCake (finished Acting Lessons, currently making Being a DIK, 8500 Patreons), NLT Media (finished Visiting Aunt Sara, My Summer With Mom and Sis, Lust Epidemic, currently making Treasure of Nadia, 10588 Patreons), ICSTOR (finished MILF's Control, Incest Story 1 & 2, MILF's Villa, currently "making" Milfy City, 6065 Patreons). You make a game, finish it and then make a new one to keep that Patreon support. You might lose Patreons because they don't like the new one, but if you're good, you'll gain other followers.
So yeah, the dev you're defending is in the list of guys who finished games. But let's be honest, games that were rushed at the ending because he got bored with them. And now he's not even bothering to end the current one, even though people who were contracted by him claim to have done their part.