Store policy on pre-optimized units (be they laptops, game consoles, etc.) is that if the sales person cannot "sell" the service to the customer, and the last units are all pre-setup, the customer does not pay for a service that they do not want.
Store policy may well be that. Reality, however, is not. As I've experienced on two separate occasions. "Sorry, we cannot provide the service for free, and it has already been performed."
Often times a customer will gladly pay the 40 bucks for a laptop with no trial software, a full battery charge and all updates
"No trial software" - I saw this once. They'd deleted the icons from the desktop. Not even from the start menu. "A full battery charge" - with LiIon/LiPolymer batteries, the last four laptops I've taken from their boxes had 99%+ battery charge on first plug in. "All updates" - potentially valid, but it's not like manufacturers don't slipstream.
a simple call to the corporate number would fix that issue if it ever occurred to you
I'm not the Best Buy Sales Policeman. Instead I'll go home, and buy it online, and Best Buy will get none of that sale.