Thanks for the spoiler! Do you really think there's anyone here on Hacker News who wouldn't get the joke without needing you to explain it to them?
The point the song makes is relevant to the conversation, and the song's well worth listening to even after you spoiled the surprise, if not just for Tim's facial expressions.
I posted the link because I believe his humor is a relevant path to enlightenment, not just an end to itself.
Are you suggesting it's good manners to reply to all the jokes on Hacker News and preemptively explain them for people who aren't native English speakers, and it's prejudiced to be against that? (That's a rhetorical joke. Please don't reply and explain it.)
And him giving the detail allows all the people who can't right now look at a video a chance to understand your point, and I don't see how the explanation detracts from the argument.