I like this Larry Wall quote:

"By policy, LISP has never really catered to mere mortals. And, of course, mere mortals have never really forgiven LISP for not catering to them."

I say this as someone who's prototyped several things in Scheme before porting this to other languages.

Because it's a funny little stereotype that has a grain of truth to it (come on, you've never heard of "old Lisp greybeards"?) and at least in my mind isn't insulting. At least, if someone implied I was a bearded old programmer, I'd be happy to be included with the likes of McCarthy, Ritchie, Kernighan, and Thompson.

Now, if we were talking about Python and someone said, "the main peril of Python programmers is that they'll get apple juice and crayon all over everything", that would be insulting!