Krensky
First Post
In the real world, this may generally be true (though even here there are situations where making sure someone isn't faking makes sense).
In a world where magical healing could make bring that guy back into the fight in short order, making sure he stays down can (situationally) be a the best move available to team monster, and I'd expect reasonably experienced warriors to be aware of that.
Which is why the medic is a primary target. Stabbing the guy unconscious and bleeding out is very low priority compared to putting his friends in the same condition. This is true regardless of magic or tech. The point isn't that people wouldn't make sure their enemies are dead, it's that you donm't do it while someone else is trying to kill you. If your average NPC is taking the time to kick your PCs when they're dying and rationalizing it as "Well, someone may heal them." you're metagaming.