The comic medium is still alive and well, thank you. Not that I'm a big fan of it or anything, but there are a few series that I do follow. And since when have comic books been "cool"? I've always linked them to the nerd crowd.
Now, I can't speak for everyone, but this is my view.
I read the ones that you don't like that much. Why? Well, the MAIN reason is that HERO comics randomly BOLD words for unnecessary EMPHASIS. It GETS really ANNOYING. Especially WHEN they START bolding words that AREN'T even important. Can you see my point?
There is only series that I read that does this (AD&D), and that's only because I love the art and characters. It's also hard to find, so I only end up reading one issue at a time with great amounts of space between.
The second reason I avoid this type of comic book is the awkward and highly unrealistic dialogue. I have seenpeople say corny lines like "They'll never spot me!" outloud while right behind someone. And, worse, is the awkward introduction and unnecessary details. My favorite example of this to point out to friends is a scene in AD&D. In this scene, a mindflayer comes out of nowhere and starts to attack the heros, saying something along the lines of "I am (insert really out of place name here, something like "Robert") the Mindflayer! Prepare to fall victim to my psychic attacks!" While the heros are already lying on the ground, writhing in pain. Seriously? Did you really need to introduce yourself like that? And a little late warning them about the psychic attack... Not that they'd even be listening at that point...
And finally, I don't like the hero comics because I'm young. Because I missed their peek, all the ideas and plot twists and so on are old and predictable. I like to be surprised and maybe even a little confused by what I read. A good example of this is the series I just finished about zombies (think that was what it was called, too XP). I was engrossed the whole time, wondering if the characters would survive. The plot twists were surprising and creative, and the ending was rather unique. That's the kind of comic I like to read. I loved it and I don't even like zombies!
Anyway, it's all about opinion. You may think comic books are stupid, but I think that wearing makeup and low-cut shirts and going out to parties is stupid. But who knows? You might like going out to parties. And I like (certain) comic books.
Also, I do read books. Right now, I'm reading Dragon's Wild, Starship Titanic, and Dante's Inferno. Yes, all at the same time.