The extra cost, power drain, work for the CPU and GPU to do - why?
I'm all for better screens - far too many laptop manufacturers think it's okay to ship large, low res screens - but 2048x1536 in 10"? It's pointless. I understand they want to give it a wow factor, and they want to neatly scale things by doubling, but this is over the top.
Hell, 1400x1050 would be more than adequate.