The problem is consumers unwillingness to pay more for higher quality displays, or even overall construction. Higher quality costs more, always. The average consumer goes to Walmart or Best Buy and buys the cheapest laptop for their needs. You aren't going to look for things like display, as that's not mentioned in the specifications (the resolution may be, but that's not enough). If you have two laptops side by side, one with higher quality display costing $100 more, the consumer is most likely going to buy the cheaper one.
Of course, when we enter the premium PC market (+$1000) where Apple is, then people start to think their purchase a bit more. They use forums and other sources to figure out what's the best laptop for their needs. When you buy a laptop because you just need something for checking email and Facebook, you aren't going to spend a lot time on searching for the best deals and so on.
When you buy small quantities of higher quality displays, the price will be more. It seems that OEMs aren't ready to take the risk of buying a million higher quality LCDs to get the price down, because they would still be more expensive than a million low quality ones. You either end up selling them for very low profit or even at loss if the consumers simply won't buy it.