I think a big part of why it took off and lives on as a meme in the internet forums sense of the word, was the familiarity of the bizarre and unnatural phrase to the young adults using those forums who remembered it from biology class.
Certainly that’s how it was for me because before Digg, or Reddit, even before Facebook (though I guess not that long before), I had had that phrase uttered sincerely as part of my education and it was so uncanny and funny to see that this highly specific and distinctive phrase was used rote, word for word, at schools all over the world and was as memorably unhelpful to others as it had been to me. Perhaps the positive feedback loop from this phrase’s new life on the web really has fed in to education in a life imitating art kind of way like you describe, but I can assure you it definitely predated it’s status as a joke, and that’s where that joke came from.