Why do you think machine gun crews were likely to be killed by the enemy foot soldiers if they were captured?

Machine gun crews were likely to be killed by enemy foot soldiers if captured due to the strategic threat they posed on the battlefield. Machine guns could inflict significant casualties and disrupt enemy advances, making their operators prime targets. Capturing such crews could also demoralize the opposing forces, but allowing them to live could risk them being used for intelligence or retribution. Consequently, enemy soldiers might feel compelled to eliminate this threat permanently.