Completely and utterly false. Lisp's s-expression syntax is trivial to parse because it is so regular.
The thing with imperative programming
Common Lisp is multi-paradigm, as mentioned in the site's FAQ. You can write imperative code all you want.
For example, IME delving into the codebase of hunchentoot was way easier than django's.
Because I've done more Python working, reading Django's source is much easier for me than most Clojure code (even my own), but that's not to say the same for everyone else.
These are after all languages (even if they are artificial). The human brain is really good at understanding a wide variety of linguistic constructs, the main issue is familiarity and that changes from person to person.