It wouldn't be funny since it's all about visual sight gag. Look at the gesture for "man". And the gesture for "real" as in "reeling in a line on a fishing pole" he did, and so on. ASL wouldn't be funny to a hearing audience.
And THAT is the GAG... probably mislabeled and all that... what do you expect from hearing people who originally posted the video. Even the artist who is a comedian (there's your first clue) ...
It's a joke and so should be taken that way.
I thought it was great and loved it... the original was pretty good but this time with the actual singer pantomiming along with the comedian was pretty good.
Don't take stuff like this too seriously... we're too damned PC in this world already. Lighten up!!