No, you don't.
You get superarmor frames, which you would even have more of if you stayed on the ground.
But the point of rolling back is to get out of the way so you don't take any more hits.
And Though it does go more than one direction, the direction is set for you from the moment you are hit, and it usually is backward, so I wouldn't talk about him not having the skill.
Well, that doesn't really help since you're still rolling away from the boss. It looks like you have to be hit from the side or back to land on your stomach, which would have been the same if you were hit from the front in terms of the location you're rolling towards. Still not really useful from my experience.
Totally agree with roll is useful moving you out of damage. And I usually want to roll out, instead of rolling back into the boss' incoming attack.
They should add an ability to choose where you wish to roll.
Rank 5 8D?