What I mean is that no one will stop you. When you ascertain your own right to do it, it doesn't mean much that I don't believe you are entitled to it. It's pretty much common practice. That is more a semantic matter at this point, but yes I stand by that being messed up for a project the size of Nix.
I don’t think that being a dictator for your project is necessarily “toxic”
Yeah, it is not necessarily toxic. It is at a lot more risk of being, though. Even a collectively managed project will mess up and upset the community, but then there is a sense of shared responsibility and more deliberation on what to do. With a BDFL, it's just whatever. After your project reaches a certain size, that risk keeps increasing... exponentially.
I have projects that take contributions and I work on others that do not
Precisely. You see, if we take this into the context of a smaller project, specially one managed by a single person as you seem to be coming back to, that is a very different context. I don't think an OSS maintainer should be laboring physically and emotionally to meet the demands of users. That is a well-known problem there. If this person doesn't even want to have contact with the community and just ship code once an year, fine. They are just sharing things with the world at no cost. In this context, "suck it up and just fork it" is indeed the way to go.
When you take something as big as NixOS though, that can really be inverted. Now you have a very large number of people who are laboring physically and emotionally to sustain a very large project, and the original creator shifts to a very different place to. It's another discussion entirely.