And his secret to winning big was "write lisp software, have it bought out by another company who will rewrite it in a different language to make it popular and useful".
Really, if PG's "LISP, how to win big" was as compelling and important as he tried to state in that essay, every ycombinator company would be using LISP for their secret advantage over other companies.
Applicants would choose LISP because it's "better", LISP-based applications would be preferred because the applicants have an advantage, existing companies would be encouraged to LISP because it would help them do more for less employee numbers and YC would become a LISPy community of alumni.
I have no proof that this is not happening right now, but would you bet on it happening right now in secret?