snake_case seem to be the convention in most of the C sources I've come across. camelCase is more comfy to type. Is there a good reason not use camelCase instead of snake_case?
I think a source of problems might be that identifiers tend to "leak" onto the filesystem (like when you name a file after an identifier), and some filesystem might not handle case-sensitive names well. But is that still a thing on platforms of 2015 worth porting to?