What they all said. That's a value shove from the river. Given how the board ran out a bluff is suicide here, unless villain's a total retard.

About him not playing KJ this way, what you said interests me. Do we have enough reason to believe that? I mean have we really seen him take another line based on a similar situation? I am not saying this is KJ only, but when you said that it's the only hand that makes sense, it could still be possible couldn't it? Anyway KJ, sets, QT and Q9, they're all in villain's range and all could possibly play this way, imo.