If my dad had enjoyed the success Ashley's had, I would sure as heck pay a lot of attention to his advice. I'd be a fool not to.
That said, I have felt the PSU connection would be hard for tOSU to overcome. But then I thought it through as if I were his dad -- tried to walk a mile in dad's moccasins.
Seeing Joe Pa as he is today, in contrast to how he must have been when Ashley played for him, might actually have been a turn-off. As a PSU alum, he knows the program has been miserable recently. So he has to be convinced that this shell of a man, at 70+ years old, is going to turn it all around and provide his son a chance to play on a great team. I wouldn't buy it if I were Mr. Ashley.
So then the choice comes down to tOSU or USC. Nothing bad you can say about USC -- great coaching staff, great warm weather location, NCs within easy reach. But it's way the heck over on the left coast. TOSU, on the other hand, has great coaches, has obvious NC potential and is a short plane ride from home. If Walker goes to tOSU, dad can watch him play all the Big Ten teams in his home region, including Minny and PSU.
If I were his dad, I'd let Walker know I'll support whatever decision he makes, but I'd also make it known that tOSU would be a great choice from my perspective.