What does it matter if the developer still cares about the project?
It isn't crashing and no new features are needed. If it did then the project wouldn't be complete.
We're not talking about some early access half broken NPM package here, the blog specifically talks about a completed product.
For you it is.
But for a maintainer, reviewing and accepting a pull request can still be a lot of work, especially if the code has been stable for a long time.
Of course there will be some maintainers who are simply not interesed or unable to offer paid support (e.g. due to their employer being a control freak) but that's ok. As others have pointed out, forking / maintaining out of tree patches (and providing them to others) is not inherently hostile.