I think we have some examples now where being proprietary ultimately created competition from open source instead of being a moat that protected anything.

Like GitHub vs Gitlab, the people most-affected by GitHub's restrictive code licensing is Github themselves wasting time and effort giving any fucks about it and losing customers anyway. Their proprietary license protecting their code set competitors and intentional clones back days, weeks or months ... years ago.

Restrictive open source licenses seem equally pointless, it's just more clear how you specifically do what you do in what may ultimately be one of many suitable approaches people use to compete with your version.

I feel like we should be using public domain much more and have let ourselves become very distracted by imposing restrictions on our code.