No matter how good the management are at predicting future cash...

No matter how good the management are at predicting future cash flows circumstances beyond their control may impact the companies ability to collect those debts. They may cause short term delys or cause fundamental changes to the collectability of debts.
In that context it is worth pointing out that PNC has not been operating during a recessionary period in Australia & in fact increasingly fewer people have actually experienced one in their adult working lives.
No approach is bulletproof but rather using the best fit which is what PNC are arguing by using FV.

Fully support your comments re time shifting having had personal experience in achieving this under the noses of auditors using the same 'experience of historical performance' argument.