Welcome, Please make yourself at home, grab a seat, play some cards, inflict merciless punishment to the US Imperialists, have a hot beverage. In time-honoured tradition of our group, the weekly discussion thread.
It comes from gaming originally I think, where someone might complain about a mechanic in the game or tactic the other players use and someone responds with "skill issue" basically blaming the person complaining rather than examining whether the game has issues or not. Very common in very competitive online games, but outside of that I think it is mostly used ironically.
Besides what others have pointed out, it's funny to use the phrase on situations where no reasonable person could think the issue was a lack of skill. Kind of like asking "vaxed?" as a response to someone dying in a car accident or something.
Oh, I see. Yes, that's closer to what I thought it meant but then I've started to see it be used around here or maybe on hexbear. Thanks for the example.