Because Jason found the video (on Precipice) and Charlesmigli apparently reads Jason's site. This is precisely what YouTube allows embedding for, sharing interesting videos.
As for not adding any value, I think the link to Instagram was valuable. Almost everyone who watches the video wants to visit that page but it is not linked on the YouTube page.
I don't care what Jason does on his website. I do care when people don't post the original source.
Some sites are worse than others. This site isn't bad (I trust the people telling me so) but still, this instance? It's just a YouTube embedded video.
I think the added value that I've missed is "approval[1] by Jason K." - seeing it's from his site means people are more likely to clicky the HN submission. That's fair enough. I just need to remember it, I guess.
Sorry if I was grumpy! I don't think I was.
[1] Approval isn't a great word. "Collation" or what ever fits too.
As for not adding any value, I think the link to Instagram was valuable. Almost everyone who watches the video wants to visit that page but it is not linked on the YouTube page.