This isn't unique. Look at a few other 'sports'.
Golf. person with the best final round isn't always the winner.
NASCAR (Neandertals Accelerating the Speedy Consumption of Americas
Resources). You have a two level competion going on, the weekly race
and the (your sponsers name here) Cup series.
NYC Marathon, overall winner and top USA runner.
With all the fans of those, you would think anybody could understand
the concept of having 2 winners in 1 event or cumulative time/points to
determine an overall winner.
I do agree with not allowing foreign pros in the US pro race. Anytime
you mix categories, the weaker group is affected by the stronger,
giving you a distorted view of the abilities of the weaker.
Given the huge effort involved in Philly, I think it will be very
difficult for a anyone to organize a similar event on such short
notice. You can expect a huge drop in the overall quality of the event
next year, assuming anyone gets it together by then.
Lastly the date. Memorial Day Weekend is a busy race weekend already.
Moving the Pro race will mean cutting the pros out of pretty much all
other races scheduled. Better to stick to the existing pro nats time
period for all the other countries. Aren't most of the countries' pro
races held during the same short period of time? Why shouldn't UCI
dictate that all pros have to race their own race and not allow them to
enter any other on those couple of days.