Jor-El's response takes longer to come than the last. "Kon-El we left alive." In the state of mind he had been in, while Kon-El's status as a hybrid made the youth less valuable- as though that was something easily applied to a living being, much less a family member- he was still potentially useful, and therefore mattered.

"We didn't check to see if Bart survived." Or if what they had done to him was even survivable.

Bart had not mattered.