Why would any sane sniper shoot medics to death? What are they, instantly healing combatants to full hp? Even if snipers would be so evil, it's much more demanding for the enemy to have wounded people because it distracts and takes off resources.

Sniper tactics is completely different from shooting non-priority targets, it's usually enemy leaders, machinegunners, other snipers and so on. Medics are civilians and only provocators would choose them as targets.