The phrase is everyday spoken French, with cons being a vulgar, familiar word for idiots or dumbasses, which gives the line its blunt force in French speaking online spaces. Short reaction clips like this spread through soundboards, messaging apps and short videos because the meaning is clear from tone alone. It has become a reusable punchline for moments of collective disbelief, especially when an explanation fails or a decision is indefensibly silly, and its brevity makes it easy to replay, share and drop into edits.