Leading to Certain Doom

Monsters should really surrender more. Ignoring the awkward moral choice it forces on the PCs (spare the monsters or execute them), somewhat intelligent monsters should have some kind of survival instinct and throw down their weapons or attempt to run away. But a disproportionate number of monsters fight to the death and eschew trickery or selling out their comrades as a means of prolonging their life.

I imagine most monsters wouldn’t offer to be merciful, and so they expect no mercy in return. So the concept of surrenderĀ seems foreign.