Doesn't YC target people like us, as opposed to the mainstream?
I think that even for programmers, Y Combinator (the fixed point combinator not the company) is somewhat obscure.
I think he meant the name 'Y Combinator' is also similar. It has significant meaning to those who know what a Y-Combinator is. For others, it's just a cool name.
i originally misread it as "gremlin", those little devils that do annoying things when no one is looking.
I doubt the resemblance is a coincidence: greplin appears to be a portmanteau of grep and gremlin. (IMHO, it's a great name.)