[tgv]

As the other comment says: readability. ALGOL-68 (infamously) allows spaces in identifiers, which makes the code look a bit more natural. C and it's descendants don't, so a logical recourse is using underscores, or --if that's too much typing-- switching capitalization. Pascal was at the forefront of this convention (weirdly enough because the language is case insensitive, I think).

Other conventions were added: e.g., a capital for a type name, m as a prefix for class members, and of course a leading _ as an indication of not being public (which comes from the unix linker/, IIRC).

Anyway, I think the answer to OP's question is a negative number.