The joke is how much attention was given to such a non-issue. Thousands of Gorillas die everyday, yet so much attention was hurled onto one gorilla that was already in it's old age, and was killed for a fairly legit reason. So stuff like "Dicks out for Harambe" and other hashtags like that are meant mockingly to poke fun at people who got so worked up about the whole thing.I still don't understand the Harambe meme.
Is the whole thing based on acknowledging he died or something?
However, vids like the one in the OP completely miss the point and just laugh at the lolsorandom aspect it.