I guess it makes sense for Apple to cheap out on displays since the MacBook itself is priced as a consumer but still put a decent display on it at least...doesn't have to be high end
Marketing perspective:
Why would they? Sorry to say but due to technology being so advanced now, Apple needs to somehow differentiate their product lines. I would submit that about 90% of the people who buy a MB never consider the screen quality. Apple is not going to enhance a product like the MB with a better screen when most people won't even notice. They will eventually add LED technology to it, but not because the MB should have it, rather they will do it because of the green aspects surrounding LED screens and the mounting pressure from green Earthy organizations.
People who buy a MB aren't interested in buying the best. They are buying an Apple consumer product because they are drawn to the design, Apple brand, and the OS. Most people who are concerned with screen qualities like pixel density, and sharper images are people who are willing to pay a premium with the MBP. And honestly, people who are truly concerned with the best technology aspect of a high end laptop aren't buying Apple anyway. Apple doesn't sell the best technology in many of its products anymore. They have realized people buy their products for design and the OS more than the actual function. You can get an ugly Dell for function, Apple represents sexy radical innovation for the sake of better design, not enhanced performance or technology (not all of the time, but for the most part).
The hardware inside the 2 laptop lines (MB or MBP) are essentially the same except for a graphics card. The real difference is the screen, aluminum, graphics card, and higher prestige. If Apple didn't include a lesser quality screen on the MB people would have one less reason to splurge on the MBP. Apple needs MORE reasons to make that jump, not less.
