I'm genuinely curious, because it's the first time I hear someone saying it's poorly written to the point that it's used as an example of how not to write in C. In fact, I often hear the opposite from people that are way more skilled in C than I am.
I care a lot about code quality, both performance- and readability-wise; so much so that I regularly check the code with static analyzers, ubsan, build the project using two different compilers with a bunch of warnings turned on, and, of course, I'm always refactoring stuff so it's more readable.
If you could help me understand better what you mean specifically about "it violates C standards", I can keep improving the project.
In time, "gratuitously using unportable APIs" isn't really a fact. There are some uses here and there of unportable APIs (such as epoll, maybe a call or two to some pthread_*_np() function), but I believe it's better to support something I know inside out than a platform I have no familiarity with. Maybe "gratuitously" could be removed from that affirmation. Also, I follow the OpenSSH idea of portability, which seems to work pretty well for them: http://www.openbsd.org/papers/portability.ps