I don't read comics for a couple reasons.
1. They tend to explain too much. I've noticed they frequently break the "Show, don't tell" rule. As far as I can tell, this is mainly used to give exposition within a single frame, but it's like trying to read Lord of the Rings: Too much exposition distracts me from the actual story and makes reading frustrating.
Granted, I haven't read many comics. The most exposure I have is from Kevin J. Anderson's Star Wars comics. That guy's a terrible writer, so maybe he's an exception rather than following the rule.
2. Especially with superhero comics, if you didn't start reading them from day one, you're going to have a hard time getting into them. Serialized comics are like soap operas in that respect. I find it nearly impossible to get into long-running comics because of all the cross-overs, parallel universes, and the fact that the continuity spans decades. And continuity resets don't encourage me. I look at those and think, "If they're going to pull that, why bother?"