To be honest, I thought pretty much the same about the movie industry. I see almost zero difference between a DVD movie and a blu-ray of the same movie. There's a limit to how much the human eye can see so what's the point of cramming more pixels into the same square inch? If only they placed more extra content in the extra space a blu-ray provides I would see a reason to move up, but as it is now there's very little incentive for me to buy a more expensive device to play more expensive movies that look the same in the end.
Of course some might say blu-ray movies present enhanced audio over DVD and we would fall into the same argument. There's a lot of difference when I hear a 192kbps MP3 song and a 320kbps MP3 of the same song. There's zero difference between a 320kbps song and... now that I think about it nobody tried to go further in audio quality. Go figure.