Part of the problem is releasing things under particular licenses that don't actually list expectations that one silently has.

Is there some agreement stating what "contribute" means and what amount of it would be sufficient?

I understand the general intent that most people have when they say they want companies to contribute back to projects. But vague wishes and desires are not the same thing as a legal licensing document. It's ridiculous to get mad at a company for not doing something you never told them they had to do. The whole point of a legal document is to hold people accountable when they don't do what you think is right.

I think the dude is grasping at straws to destroy a competitor and looks like an asshole in the process. He's trying to go back on terms they didn't set and agreed to years ago. At least from what I've seen of the issue.