> That open source software forms some part of a commons is not really a thing in practice. Open source software is ran by maintainers, those maintainers own the projects, and they do with the software what they deem fit.
One should make a difference between (1) access to the source code to look, find bugs, make minor adjustments and (2) everybody with that access to be able to actively participate in the development.
In the sense of (1), open source is "some part of a commons". That's what the license gives you.
In the sense of (2), open source may or not be open to a community approach. It's fully legitimate for some company or other group of maintainers to provide (1) but deny anything related to (2). You are free to fork and make your own community, but there is nothing that guarantees you that your pull requests are accepted or even looked at, bug reports reacted to or anybody listening to wishes, concerns or other opinions about the project. It's nice if that's provided, and one could argue that some part of the spirit of open source is to enable a community, which in turn helps the original creators (and could be a major motivation to open source something), but nobody should be upset if maintainers choose otherwise.
It's nice if it's clearly communicated how maintainers see this though.