Some of my favorite quotes about X ( from http://quotes.cat-v.org/programming/ ) :

"Programming graphics in X is like finding the square root of PI using Roman numerals." -- Henry Spencer

"Sometimes when you fill a vacuum, it still sucks." -- Dennis Ritchie speaking about X

"If the designers of X Windows built cars, there would be no fewer than five steering wheels hidden about the cockpit, none of which followed the same principles – but you’d be able to shift gears with your car stereo. Useful feature that." -- Marcus J. Ranum

"The X server has to be the biggest program I've ever seen that doesn't do anything for you." -- Ken Thompson