I'm sort of a lapsed comic geek - thanks to the Internet, I'm able to still have a good knowledge of what's going on in comics and what all of my favorite characters/teams/universes are up to, but it's not truly cohesive.
I think a lot of the issue with being into comics has to do with there being like 50 different continuities and stories going on at once with no real way to pin them down and be like "this is the main thing, this is the pertinent story". There's a main continuity, and then there are alternate ones/side stories, and then there is the continuity in different media (like whatever the current cartoon/TV show is, and/or the current movie) - it makes me feel like if I'm not a top-tier comic book guy like Spike Spiegel or something, I can't truly participate in the comic fandom and I'm just as knowledgeable as some guy who just has the latest movie on DVD.
Also, how do you even get a comic nowadays? When I was a kid, you were able to get these things at your local coffee/magazine/deli spot, or in the local drugstore (whether it was a mom-and-pop thing, or a Rite Aid/Walgreens/CVS type thing) in addition to the comic book shop. You used to be able to subscribe right out of the back of comic books too. Now, you are fucked if you don't have a comic book shop nearby, since those stores and delis don't sell comics anymore. At least living in NYC, I can hop on a train and find one...but if I was a kid today, I wouldn't even know how to get my hands on these things since I can't reach that comic book store that's far from my house, and I don't know if you can even subscribe anymore outside of (possibly) the Internet.
...then again, I bet none of those things are really the problem. Comics could be too pricy now, too - each one's like $3 to 5, and for a kid that's a lot of scratch. Who knows, really.