Seems they were trying to hard and it just backfired. The humor wasn't intended as a negative thing but it's good that they apologize to clear the air of uncertainty.
I actually know Avand personally, and his humor is often awkward, as is common in many geeks.
I can see where he was trying to go with the joke (exactly where he said he was trying to go in his equally awkward apology), but once you trip up on a sensitive topic, people immediately arrange themselves to be maximally offended. Once this happens, anything short of a blood sacrifice is insufficient, and woe be to anyone who fails to make a 100% flawless apology!
So for the socially awkward, the result of a failed joke is a bad situation that it's impossible to get out of, because nobody is willing to accept that there exist people who are less than perfect when it comes to the social dance.
Its fine to be less than perfect and to make mistakes, but if someone makes a mistake large and in public, they should apologize for it. Spending the least little amount of time talking to someone who was offended should be enough to clue in the clueless, and ensure a genuine apology.
An insincere apology shows that the person apologizing really cares less why anyone actually was offended, and is just as likely to say something equally offensive again.
Once again, it comes down to a difference between what each person considers an appropriate apology. What you usually see (including in this case) is an apology, followed by people arguing over whether the apology was sufficient or not. "Sincerity" is gauged based on whether you think the apology is good enough. If not, the usual response is to say that the offender obviously didn't care enough and is being insincere.
Never attribute to malice that which is adequately explained by stupidity.
The social awkwardness of their joke kinda shows the divergent nature of the "brogrammer".