I only found it because I had the same idea, otherwise I wouldn't have known it existed.
It is a fantastically useful project, but if no one knows about it then it's not. In your blog post mentioned:
After I found that, on GitHub alone, there were more than 36,000 issues asking "Is this project abandoned?", I thought about how to tackle this problem. More than 15,000 of these were open issues. So, lots of projects need help with their maintenance.
So, how do we connect those projects with this one?
I would suggest a nomination feature, where people can nominate a project, and then others can vote on it to give it more visibility. I realize you already thought of this:
First, I thought it might be nice to have a dashboard that rates OSS projects by whether they needed help with their maintenance. When I had a prototype running after a couple of days' work, I found that it kind of worked but did not really overcome the problem of getting into contact with the maintainer. And when a maintainer was hard to reach when I needed support, it would already be too late.
So how are we getting in contact with the maintainers now?
A nomination feature could put some visible pressure on the current inactive maintainers (e.g. "look, many people want this project to stay alive."). I suspect many of the inactive maintainers aren't even thinking about those projects anymore, so expecting them to come here (without even knowing this exists) and submit their project(s) without a little nudge is unrealistic.
Maybe even have a notify feature, when enough votes have been cast for a project you can either tweet at the person (if their github has their twitter listed) with a link to the project nomination on adoptoposs.org. Another way would be to have a separate github repo for just issues that are autogenerated and tagged with the person's github handle.
There are other ways to get this out there. Maybe contacting large multi-part projects like GNOME, KDE, MATE, etc, that have many smaller parts that lack maintainers. Those projects will most likely know already which one of their smaller programs are in need of maintainers.
Another way would be to start with those 15,000 issues mentioned above, sort them by number of github stars, and then contact the top 100 or so manually.
Another feature that could be useful would be to try to lure the currently inactive maintainers back. Combined with the nomination feature, you could have a sort of pledge system where people can pledge to support the project financially (e.g. through Github Sponsors, Open Collective, Patreon, etc.) if they start maintaining the project again.
Obviously there could be some issues with people following through with those pledges, so those kinks would need to be worked out.
Perhaps it would be enough to get the maintainers interested again.
I also think the github stars and date submitted should be listed on the projects page.
Also, add the website name to the README. I know it's listed in the description, but it should also be prominently displayed in the README.
Anyways, that's my 2 cents worth.