I suspect this is because OSS software on Patreon usually doesn't come with many actual benefits. One of the models I'm interested in playing with in the future is having Patreon-specific issue trackers and access to separate development repositories.
In any case, you should not be trying to fund yourself purely through Patreon unless you have a good reason to believe you're going to be different.
Kickstarter and crowdfunding on the other hand has been real promising.[2][3][4][5]
I think there's strong evidence that OSS developers should consider charging upfront for feature development. It probably doesn't work for every type of project, but it seems to work for many types of projects.
[0]: https://liberapay.com/explore/teams
[1]: https://marijnhaverbeke.nl/fund/
[2]: https://www.kickstarter.com/projects/1681258897/its-magit-th...
[3]: https://www.kickstarter.com/projects/aiforeveryone/mycroft-m...
[4]: https://www.kickstarter.com/projects/johnonolan/ghost-just-a...
[5]: https://www.kickstarter.com/projects/mbs348/diaspora-the-per...
This is the other problem I ran into trying to figure out how to get Patreon set up - Github and Gitlab have pretty broad permissions.
It would be good to see people experiment with a wide variety of permissions surrounding issues, from access, to commenting, to creation, to upvoting. A lot of Open Source projects aren't even really looking for funding, but still want something in front of people who are just showing up to complain.
I don't know of a public issue tracker that supports that kind of granularity though (if you do, let me know), so the next best thing I could find is to make a private group on Gitlab for development branches and issue tracking, and then to mirror everything to a public repo for stable releases with issues disabled.
If anyone who works on Gitlab/Github is lurking around, it could potentially be a really cool differentiator to have those kinds of granular permissions.