LCD vs LED
I imagine they couldn't go with LEDs because it would make the display astronomically expensive. Nowadays most LED Displays are built as LCDs with LED backlight located on the top or (in more expensive models) around the circumference. As a result, backlight only shines around the edges and special diffusers spread the light evenly over the whole screen. Seems like it would be tough to have even brightness/contrast on a screen of that size. Alternatively, they could build it with OLEDs, but we're talking REALLY big bucks there.
By the way, if your 23" monitor had resolution higher than 1080p, you would have a really hard time seeing things on it because objects would be simply too small. I'm just saying.
