In our society, why should they be expected to build for free? Unless you only hire previously wealthy individuals the idea that there's this class of selfless scientists at the top of their field that don't need to pay a mortgage or support a family is absurd.
In case you do not understand why you are being downvoted. This is precisely what the person you are replying to is saying. When push comes to shove, will these builders prefer a paycheck or stand on their principles.
Tell me in which country Linux was first developed?
Which part of the world is that?
Do the countries there have something special which they are well known for, and which might make unpaid passion projects more attainable than, say, 2020s North America?
Ilya signed the letter, too, and has posted an apology[0].
[0] - https://nitter.net/ilyasut/status/1726590052392956028?s=20