You must have watched different games last year than I. Towards the last half of the year, I found that PT was surprisingly unsuccessful carrying the ball. In the beginning of the year he was fine.
I don't even have to look hard to find that their averages are identical with Ingram getting 2.5x the amount of carries.
Not to mention the fact that PT is an amazing check down option and a better pass blocker.
There is something to be said to the "stack the box" angle, but even so, there are also extra blockers to open gaps.
I don't think people here give a crap if Ingram is given a longer leash and a chance to succeed. They just don't want a 3.3 YPC Ingram rushing 250+ times this year.