Personally I need to be able to jump from thing to thing on the screen since my attention is... well.. very deficient.
I guess I'm lazy in some ways too. I would rather be able to see my stats go red than to have to hit 'P', take up more space with a large window to find what I need and hit 'P' again and hope something hasn't happened
(Damn Tidal Walkers...)
Some people are comforted by their numbers
Some use it to track their Uberness even. Some are plain lazy like me
Also like me would be the people that click everything and not use many hotkeys. This easily creates clutter in and of itself! OMG my Chat windows take up too much space... I really do need to fix that!
It comes down to gameplay. Its not wasted gamespace if its useful to you.
Would a counter-point be: MUDers would think all your graphics is a waste of gamespace too :P (JK! hehe)
-Selae