Eric Powell, writer/artist of The Goon, released a video over the weekend (link is safe, but video is NSFW) about supporting diverse content in creators in comic books. In it, he makes some decent points. However, those points are completely overshadowed by some gross generalizations and crass content.
As Marshall McLuhan once said and millions have restated ever since, the medium is the message. And when your medium is a representation of a corporately owned superhero forcibly sodomizing an independent comics creator, well, anything else you're trying to say is going to get lost in the shuffle of discomfort and homophobia.
Should you read comics besides superhero books published by Marvel and DC? If you find ones that appeal to you, then yes, of course you should. We're in a period where there is probably more content available in more genres that at any point since the Golden Age. In fact, we've got a huge one up on the Golden Age in that most of it is, in fact, of high quality and not rushed out the door by teenagers working under near-sweatshop conditions. There are multitudes of great comic bookery going on right now that can and should appeal to nearly everyone, even a lot of those folks who think don't they like comics. Seek those out. Buy them. Read them. More great cartoonists making a living wage off their good work and being able to produce more of it is always a good thing.
But if you like Marvel and DC superhero books, you should feel free to read those, too. I think Powell's intent would have been better served if his message was more along the lines of "if you like these things, then give these other things a shot" instead of "if you don't buy the things I tell you to then you're a bad person and you're ruining the entire industry and by the way BUTTS!!!! LOL!!!!! AMIRITE?!?!"
Like what you read, read what you like, and vote with your wallets. It's that simple.