Why is the America comic book industry dying?

I saw a doentory on comic books once on the history channel. In so many words they basicly said nerds killed it. Comic books were originally sold in stores all over like at checkout stands and they were meant to be thrown away after done with but people kept keeping them and started collecting them and it moved off into specialty stores. Once it stopped being in normal stores people just were like screw it. Then by my own speculation the American arists just didnt really give a damn or there became less and less because of the stupid economy making it hard to make money off of it.