Because CamelCase requires you to hit SHIFT a lot. Real Lisp programmers use a hyphen. More readable than CamelCase and less obnoxious than an underscore, although
call-with-current-continuation
in SchemeLanguage is a bit ugly, so real Schemers use
call/cc
Any such examples in CommonLisp?
Hmm, I'm fairly sure that Lisp would use underscores in names if one didn't ordinarily need to hit shift for them.