As someone who lists Befunge on their resume, either they get it or they don't

(I followed up an interview with a link to a brainfuck interpreter I did in Haskell https://github.com/serprex/bfhs I got a 2nd interview, but no offer)

Personally I think the author is celebrating a recent successful tenure defense.

Why? "Fuck" is not as bad a word as it used to be, especially depending on context.

And your surrounding culture. In some places, you'd be out the door before the word had fully left your mouth. In others, nobody would blink...

I wouldn't count on that. You generally want to stay away from any expletives in interviews, work and anything career oriented.