This is a case of extreme bad luck. Personally, though, I would have just kept the MacBook Pro with mat screen. It would have been a very nice upgrade from the original Macbook order. But you had every right to return it. I'm just telling you my choice. I've been through my fair share of bad luck and exchanges, with Apple and other companies, and I have learned that it's just best to accept what you get (imperfections included) and move on, or simply ask for a refund and move on. Perfection is also too hard to find in this world, certainly now that everything is outsourced and made in China. But even when it's made in Japan, it won't be perfect. After two exchanges of a Sony F-717, and somewhat being picky, I confess, I simply returned it for a refund. Months later, I bought a Sony F-828 and couldn't be happier about it. Sometimes, it's just fate telling you that you don't want a specific product but something else. Sometimes, it's not what you exactly had in mind, but when you learn to accept it, life just becomes better. That's how I go through life, lately.
P.S. One dead pixel is also usually well within specs. Some companies won't exchange if you don't have at least three in a cluster--at least, that was some time ago when I went shopping for a screen for my brother (got him a perfect Eizo screen, by the way).
You make a lot of good points. Sometimes it's best to just cut your losses and move on. I had to make a similar decision with my Macbook. It was tough, but sometimes things just aren't meant to be.