It is a tongue-in-cheek mockery of an earlier meme about "real programmers" which is a variation of the "no true Scotsman" fallacy and "real men don't eat quiche" which was a very popular book.
http://c2.com/cgi/wiki?RealProgrammer
Original thread where Wall stated this.
Monty Python version, The Four Yorkshiremen is a mockery of this whole thing.
"Real programmers" don't need high level languages, and The Story of Mel is the exemplar of this. And it was uphill both ways!