You can be too late, with respect to certain windows.

For a while, people made significant money selling highly desired domain names, including to big companies.

Now, those companies just "take them away" via trademark infringement claims. The legal structure for doing so has since been constructed and tested by them.

One of my concerns is that more and more such windows are being closed. It's not the isolated case, but the overall trend towards a corporate and corporate state restricted "push" implementation.

I.e. the end of "open".

I don't really see how disallowing people from registering a name already in use by a person or company goes against "openness". If you're using someone else's name, I think they're justified in trying to forcibly retake control of it.