In a nutshell, better picture, lower price, more channels.
Even with the surcharge, NPS is selling the movie channels cheaper than everyone else. They're also the master feeds. Both pizza and cable do a pretty good job in screwing up the picture quality with their over-compression ( I won't even go into HD-Lite). You also get more channels, not just the east and west coast feeds but also a few that Dish and Direct don't carry at all.
No, I can go to another C Band reseller and buy them without the surcharge. Again, all I want are a few HD feeds of which I pay NPS around $40 a month for - and I should not be forced to pay for others retransmission of channels - if it cost others more for that - I should not be subsidizing their bill.