See "The Blub Paradox" in http://www.paulgraham.com/avg.html on why it's hard to get this across.
The "clear advantage" that Lisp still has is the best type of homoiconicity (http://en.wikipedia.org/wiki/Homoiconicity); see items 8 and 9 in http://www.paulgraham.com/diff.html.
I'm not sure why this is hard to get across; my first introduction to Lisp was a "Learn Lisp in 15 Minutes" talk/mini-seminar/whatever and it was immediately obvious to me.