Not just that, he also seems to think that he invented Lisp's idea of code-as-data: "In most languages there’s a sharp distinction between programs, and data, and the output of programs. Not so in the Wolfram Language. It’s all completely fluid. Data becomes algorithmic. Algorithms become data. There’s no distinction needed between code and data." ( http://blog.wolfram.com/2013/11/13/something-very-big-is-com... )
Kinda funny considering how the Mathematica language is built on top of the M-expressions that lisp never bothered to implement.
Note that this is marketing copy aimed at Mathematica users, mainly scientists and mathematicians, most of whom probably don't know what LISP or Haskell are.
I think that's part of it. It's also aimed at non-hackers who took a look at Clojure once and said 'yuck'. And managers who are being 'groomed' not to totally freak out when someone on their team says "can we use the Wolfram Language on such and such a project?".
Kinda funny considering how the Mathematica language is built on top of the M-expressions that lisp never bothered to implement.