This is the same argument as "capital flight". It's a bad one as most opensource isn't used commercially. There are thousands of projects maybe millions of projects out there not found anywhere in commercial projects. Most aren't written to end up being used commercially either, but if they ever are, they should get paid.

Arguing against adding a line to get paid in case it's used commercially, is as bad an argument as taxing the rich "because one day I might be rich".

Anti Commercial-AI license