Well, they wouldn't be so bad if there was a way to reasonably keep your dwarves from randomly running out (alone of course) in the middle of an ambush, and springing another in their rush to grab xArmadillo Leather Trousersx or XPorcupine Fur GlovesX from the dead body of the first ambusher that fell.
It also wouldn't be as horrible if the dwarves actually ran toward safety instead of in a random direction. The conveniently located entrance has traps for a reason! Use it, instead of getting yourself cornered somewhere 10 feet from the entrance!
Dwarves need to run for safety, EVEN IF there are goblins in the way. Dwarves also need to simply avoid doing tasks that take them into dangerous areas, such as the middle of a hostile army's camp. Failing this, there at least needs to be a way to keep dwarves inside the outer wall without disrupting the fortress too badly.
The problem is that currently there is no way to protect your dwarves other than a. ordering them to stay indoors FOREVER, b. systematically micromanaging every item that falls to the ground outside the fortress for any reason whatsoever in order to forbid them, or c. simply walling your fortress off permanently.
Also, it is unreasonable to expect a fortress of 20 dwarves to be able to handle a surprise attack by 25 heavily armed and armored goblins. Every other month. :-P