Show me one group of programmers who don't trust their standard libraries and I will show you fools who are busy reinventing the wheel instead of getting things done (or beginners just exploring the application domain, still ignorant of the built in functionality of the underlying system. Or they might be knowledgeable programmers who distrust a lacking platform, it's not unusual for PHP, Palm Pilot or Win16 programmers to use custom libraries instead of the standard ones)

Even embedded systems hackers have libraries and API that they port to and tweak for every new architecture and configuration they're faced with.

Your statement about Lisp programmers not trusting standard functions, or at leas your interpretation of Carl's (I didn't read it that way, btw.) is patently untrue.