The term "legit skill issue" is used in the gaming world where 2 person when fighting and any one of them is not able to kill the other inspite of the fact that that player is playing the game for a long time is know as legit skill issue.
One's ability to dominate your opponent in a skill based ranked multiplayer game, yet both the players started around same time since the release of the game.
An issue that happens to be a stupid issue, so you wouldn't say that it would simply just be a difference in skill but also it would be just a downright stupid thing to do in general. Usually paired with the skull emoji.