C has an interesting culture of terse variable and function names, and limited comments. It comes from an entirely different mindset and time period in software. It predates most "modern" concepts of software re-usability that eventually turned into enterprise OOP practices and was crystalized in Java and C#.

It's not great anymore. The software world has moved on to understanding how important these things are (and even often takes things too far), but C seems a bit stuck in its ways.