I don't know about other people who read comic books, but one of the main reason I read and enjoy them is because of their longevity. This is the main reason I don't watch many TV shows, because whenever I start to watch something, it inevitably gets cancelled. I mean practically every time! This annoys me to no end, because I usually invest a lot of time and thought into the things I watch and when they are cancelled, they're gone. That's it. Those characters I'd spent hours of my life watching and thinking about are never to appear again. I HATE that. It's kind of the same when it comes to regular novels. I'd read stuff from all kinds of authors, you name em, and I'd read em. Well, once I read a story from some horror author, Steven King I think, that was like 500-600 pages long. After reading such a long book, I had formed a bond with the characters and when I closed the back cover of the book, that was the end. Those characters were gone, never to see the light of day again. I hate the finality of most forms of media. On TV, in the movies or in novels when it's over, it's over.
That's what appeals to me so much when it comes to comic books. Superman has been going strong for like what, 70 years now? In a comic book, if one of your favorite comics is cancelled, there is always the chance a new editor/creative team will revive it down the road. The same goes for deceased characters. If somebody dies in a comic book, there is always that chance that somewhere down the road they might pop up again. In comics hope springs eternal. In other forms of media though, the end is just that, the end.