Filippo is another maintainer, of extremely similar open source software with entirely the same customer base, offering (important) advice to a peer, so I don't think policing his tone is helpful here.

I know who he is and what he does. I think we probably disagree on whether that makes the comment in better or worse taste.

Otherwise, I agreed with him, and am genuinely curious whether the stopping factor here is maintainers like Frank simply not saying "you can email me to retain my services"