You returned a computer. For one bad pixel. '13 inch screen with one bad pixel.
If you just bought a brand new 13 inch MacBook Pro, and it came with a dead pixel, what would you do? Really? What would you do? Maybe he bought the laptop for professional work? Maybe he just wants the laptop that he paid for?
People buy Apple for their quality. If the quality isn't there, then why settle for it?
EDIT: I thought I should add this. I bought a Palm Treo Pro from Sprint this summer. The first one would lose it's connection after a month and had to be reactivated. So they replaced it, and the new one had a stuck red pixel. I took it to the repair center and the guy was really rude about fixing one stuck pixel. I don't care. I paid full price for this phone (about $550), so I wanted a perfect product, and I explained this to him. The guy agreed with me in that point of view and fixed it. The guy had the same attitude as you have, so maybe this will change your perspective.
...Unfortunately, he broke the keyboard in the process, so half the keyboard was toast. Called Sprint back up, and they sent me out a HTC Touch Pro, free of charge.
This is how companies should operate. Customers are always right, and they should be the companies first priority. It's better for business.
Think of how the OP would have felt if Best Buy didn't replace the laptop. I would be pissed. I would not want to go back there, and I would not recommend Best Buy to any friends. "Go to Fry's, go to the Apple Store, but NEVER go to Best Buy because they'll screw you out if the product is clearly defective. Here, want to see it?" If Best Buy makes the customer happy, like they did, I bet the OP will recommend friends to go to Best Buy to buy products.
Plus, like sharkync states below. It's not a total loss at all. The screen will be replaced, and it will be resold in Apple's refurbished store. Trust me, they're still making money.