How much would it svck if everyone you wanted to fight ran away?
A lot, but I think a lot of people want more of a sense of... atmosphere, of realism, when it comes to enemies sometimes.
You face a bunch of bandits - cocky, they have numbers on their side, they're probably off their face on skooma, yeah, they'll have a go. But it is after you have taken the majority down without breaking much of a sweat yet they continue to courageously throw themselves on your sword it becomes an issue. All the while shouting things that make it seem like they have no doubt at all they'll be gutting you like a fish in a moments time, even if that have to wade through dragon bones, troll carcasses and the bodies of all their dead buddies to do it.
I think people want enemies to act a bit more like, well, enemies who want to win but also want to live. Personally I'd be happy with a better yield system. At the moment it feels a bit unfinished since bad guys will yield and then there is nothing you can do - wait long enough and they just attack again.