Comic Strips

George Carlin (who is idolized and rightly so, mostly) had a line in one of his standup specials where he said “you show me a tropical fruit and I’ll show you a cocksucker from Guatemala”. Homophobia was just so normalized back then (this was the ‘80s).

I don't think this bit was homophobic at all, and that you've misinterpreted it, through omission and otherwise. If anything, homophobia is part of what is being laughed at (and a small piece of the overall joke). I'll explain.

To begin with, you left out key parts of the joke; he wasn't expressing that as himself. Here's the full bit:

I remember something my third grade teacher used to say. She used to say "You show me a tropical fruit, and I'll show you a cocksucker from Guatemala." No, wait... that wasn't her. That was a guy I met in the Army.

While the joke uses "fruit" as slang for gay as part of it, that isn't actually even the punchline, the wordplay is just a vehicle for it. The humor primarily hinges on the notion of a grade school teacher saying something that crass (the second part specifically) to a child, coupled with the implication that it was something she said more than once ("used to say" instead of "said").

Then he realizes it was some grunt who was in the Army with him (who it'd make more sense to say something crass/uncouth like that), which adds another element of humor in 'how could he possibly mix those two people up?'. If anything, that hypothetical Army guy is being laughed at in part for the homophobic slur usage.