I agree with Joe's decision to not release his software to anyone. He has already made several great videos on the nanoVNA which I found useful. Some people feel "entitled" to his work and this was expressed in the eevblog thread on this topic. Unfortunately there are individuals who will criticize his code, demand support and claim credit for forked versions of his code. Who needs that kind of aggravation when you have lost interest in the project as he clearly stated?
I appreciate people like Rune who publish their code, offer support and updates because it takes a lot of work to do so. The community needs to respect this kind of work and not become demanding and discourage him.
Roger Need