Once you've gotten a game or two in, you'll notice that your soldiers seem to be bailing quite a lot.
At first, this can seem a bit off putting, particularly if you are coming from other games, where troops either stay in place or all break at the same time.
The goal here is essentially to create a fluid battle field. Remember, a figure that has Bailed is not in a complete state of panic. They've fallen back and then gone to ground because the situation they were in is no longer tenable to them.
Of course, sometimes they will Bail again when you try to recover them, in which case it's a more general morale failure.
What it does, most importantly, is give a way to actually drive people out of a position. A machine gun opening up on a couple of soldiers in a crater is very likely to force them both to retreat. This, in my opinion, is more realistic than the two staying in position turn after turn, because the enemy can't hit them in hard cover.
Under heavy fire, your men are likely to pull back and it is up to you to regroup them and retake the position.
A side effect (but a welcome one) is that it also encourages players to engage all of their troops, since figures left near the table edge may well bail straight off the table.