Zedcat,
As my PT told me, the reason the "gliding" exercises are still done after surgery is two-fold. One is to exercise movement of the Ulnar to help it recover from being handled and moved. The other reason is to re-teach the Ulnar in its new home, and too, to reduce scar tissue build up around its new home.
Your scar is way longer than I have seen on anyone. Mine is just 3.1 inches long, and the one in my hand just over 2.5 inches. Wow! I do agree however that a "scar" verses hand usage or loss, I'll take the scar any day!! I too would undergo this type of surgery again if I were to say, have this happen in my other arm.
I will say this for post op PT, it is worth it! Day by day I see improvement. I am one day short of week four after surgery, and though I had my ring finger back pretty quickly, my pinky has been the hold out. It is more controllable now which is good. Today I noticed that I can once again feel from the knuckle to the first joint in my pinky.

Even if all stayed as it is right now, it is soooooo much better than before surgery. The surgeon's did their job, now it is my turn; PT, positive attitude etc. "Life is getting better daily."