What motivated that phrase is probably the plight of (non-corporate) open source maintainers who get very little money for a lot of work, while at the same time

What motivated that phrase is probably the plight of (non-corporate) open source maintainers who get very little money for a lot of work, while at the same time seeing billion-dollar companies that save a lot of money by using their software. The example of curl is maybe not the best: curl is a high profile tool, used literally everywhere, and at the same time (relatively) straightforward: it does one thing (with a lot of variants of course) and does it well, but it doesn't have as much of the "bit rot" maintenance burden that other projects have. So there are a lot of open source projects that are much more "thankless" than curl. Of course, no one forces the maintainers to give their work away for free, but then no one should be surprised if projects (even popular ones) are abandoned.