Since they've said nothing I'm going to continue to use Occam's Razor and believe that they did it either as a form of revenge or because they mistakenly believed in cargo cult of that being how stuff was done (likely thanks to Hollywood).
The torture program had much more to do with long-term engineering of a prisoner's environment with the goal of breaking down his humanity and spirit over a period of months and years: stress positions, sleep deprivation, loud music, extreme temperatures, and repeated fruitless water-boarding.
I don't think we get to blame Hollywood for this. More like the techniques that our "advisors" were refining and teaching to repressive anti-communist regimes throughout the 20th century, finally applied by us instead of by proxy.
When I was a child/teen, it was popular to wonder about the effects of TV violence, and now we know. It appears many people are unable to distinguish between TV and reality. Monkey see, monkey do.