When I first saw heard people talking about walking Tobacco Road, I thought they were nuts. I never considered it walkable, because it is hilly...if you're on the cart part. The front 9 is actually pretty walkable and once you leave the first tee and get into the valley, it's pretty easy walking until you walk up to the green on #9.
The back 9 is tougher, and hilly. And there is a pretty big walk from #14 green to #15 tee. I can definitely see how older golfers would struggle to walk.
At first I was thinking the walks up to some of the tees would be a negative for walking, but you have to walk those anyways, because the carts don't go up there.
Either way, while some golfers might find it easier to play TR with a cart, I don't find that the playing experience is enhanced by it. Quite the opposite in my opinion.