That seems concerning and deeply cynical. Mostly because I worry that it may be accurate.
the idea that free software is primarily done unpaid is just a myth, as can be seen from the attendees of any major free software conference
I'll point out that just because you mostly see delegates from big businesses to FOSS conferences, that doesn't mean this is a representative sample. It can just as well mean that the long tail of contributors isn't able to attend.
Of course, had the maintainers of the small-but-popular tool/library chosen a license under which the big corporate users were forced to contribute any local modifications back, this may in itself have prevented the popularity of the tool or library in the first place. Because for many developers and companies, using an AGPL (or even GPL or LGPL) licensed tool or library is absolute anathema.
(GPL in whatever form of course does not help with financially compensating independent developers, so it wouldn't fully solve the problem.)
I got linux and the GNU userland for free. I used it to learn and it got me a job. Of course I contribute to GPL projects. It's not unpaid work, it's paid in code.
It's funny that he chose mongodb as an example. They require a contributor to sign the CLA and give all ownership of the code to mongodb. This is effectively unpaid work, more than the GPL.
These new unfree licenses are the most restrictive the VC friendly lawyers can think of to maintain an usurped "open source" moniker while trying to push clients to buy commercial licenses.
Yes lot of corporations get free software for free. And that should be celebrated: free (as in freedom to tinker) software is getting everywhere. People can read it, adapt it to their needs and release it again.