Comment section reminds me of those for VLC. No clue why people complain about free stuff no one forces them to use. Like, just pay someone to implement DNSSEC if you really need that in curl, or write it yourself.
> Replace this text with the error page you would like to serve to clients if your origin is offline.
Just like roads. Nobody forces people to use them, you know; sure, some people might want to use them, to go for some place for some other non-road-related business but that's just their problem.
On a more serious note: people complain about "stuff" when they try to use that "stuff" to do something and it doesn't work no matter whether it's free or not, it's just human nature. As for "forced to use"... if you need to make a network request from command line, the options are basically curl or wget. Neither of them support your use case? Well, you can always just give up and not do whatever you intended to do, nobody forces you to achieve things anyhow.
Open source software is not a public utility and not paid for with tax money, therefore your analogy is flawed.