For all those who say: "The developer quit because it was expensive to make and he couldn't continue," my answer is this.
What does it cost them? Time. I've been a metal musician in this country (Cuba) for over 20 years without making any money and spending quite a bit on it, and I always did it for the pleasure of doing it and so people would see and enjoy it. If someone start developing a game with the mentality of leaving it half-finished because he/she won't receive the amount of donations he or she like, then don't do it at all because it sounds like a scam.
TL;DR dev needs to be realistic and not expect to win the lottery
There are a few titles on this site that are passion projects for the devs, with them creating their AVNs while refusing support. There are others where the devs have set up an option to throw some support their way if you so desire. But sadly, the vast majority of the AVNs on this site that have appeared in the last several years are all heavily focused on revenue generation; people expecting to make bank and not have to work a real job. A few of them are that good that it works, and kudos to those devs. But sadly there are at least 100 would-be pro devs for every actual professional dev (skills, content delivery, etc.).
This site is littered with hundreds (if not thousands) of abandoned titles, many of them abandoned after a single update or less, because the devs didn't get the revenue they expected. It's honestly bizarre if you compare it to any other creative endeavor. How many print authors expect their first work to lead to mass success? How many musicians? How many painters expect to make bank from their first paintings?
The art quality of this title/avn was mediocre at best. The story/writing was also pretty poor. There is zero reason for the dev to expect any sort of financial success from this work. But it could be a good way to learn how to get better. Maybe this first title doesn't result in a financial success, but it could be a way to improve, iterate and learn what works, what doesn't and do better on their next title. Then, with a successfully completed project, potential backers would know the dev can actually complete a project and not leave them hanging out to dry.
It sounds like a scam, because it is. Patreon is terrible for AVN development. It rewards doing nothing. Look at all the stagnant AVNs on this site that still rake in money for their devs with no content delivered for years. Personally, I really like Steam as a way to support AVN devs, and before that Itch.io. It rewards devs for completed work. It encourages them to get more done if they see success.