I didn't understand the reference but I didn't have to quickly scan to other comments because the next comment mentioned that it was a reference.
I would also say that sometimes being exclusive can make a joke funnier to the in-group. Denoting your sarcasm can make humor less attractive, in the same way explaining a joke ruins it. Sometimes you want to be vague to see who catches the signals.
Some people, myself included, will react poorly when requested to perform additional work when additional work from the requester also could have been performed.
And not everyone else "got the joke". I'd assume many folks didn't get it, but didn't post.