FOSS is the mantra of a particular community-oriented software-development zeitgeist, where things are developed by a community, without a project maintainership per se—i.e. where "the project" refers to whatever the most active fork of the project is, rather than to the project as maintained by some particular BDFL.
FOSS projects are usually maintained under the aegis of one or more software foundations, like GNU or the ASF.
"Open source", on the other hand, means exactly what it says. Microsoft does Open Source. Apple does Open Source. Oracle does Open Source. It means exactly as little as the image conjured in your head by that list.
What's described in this rant is basically "Source Available". Open Source means more than that, per ASF, per OSI, and per many who publish software under non copyleft licenses.
To make it as simple as you suggest, there should be a code repository and nothing more. I don't think that's the case in the majority of open source projects or even what Clojure desires.
That being said, if you're not contributing back to a project (in any sensible way, not just code) maybe you should tone down your demands. I completely sympathise with author but things are a bit more complex in reality. Ignoring the benefits of these interactions/contributions is not fair to the rest of the community that is contributing. Maybe the author does that feel that's currently enough? I can totally relate.