Immature? Who said anything about us Sox fans being mature or immature, or for that matter sane? That hits below the belt.
However, your right to say that it wasn't all Koch, but in the final box he was the final screw up. He is in a position, and paid good money for it mind you, not to continue to blow games. There are plenty of others though that can be lumped in the same description as a non-producer, Lee for striking out with the bases loaded, Jimenez for not scoring from 2nd, Crede for the error, Marte for not getting the first hitter he faces out. I am sure we can analyze the game deeper and find more. It just boils down to playing unsound baseball and we have done that a lot.
No way the blame should not be thrown Billy's way. I know DJ and Carlos had their GOAT moments during the latter stages of the game also, but Koch faced just 1 batter, 1 BATTER before Jones. If it was the 12th and Koch had already pitched an inning, then fine...maybe then he's not to blame.