The above posts are pretty bang on, but I also think that DC have less top flight characters.
I don't think that's much of an excuse though. Part of Marvel's success has been taking second-tier heroes (by necessity, seeing as almost all of Marvel's headliners were already taken by various studios) and making them household names. Nerds knew Iron Man, but he sure wasn't particularly well known before his movie. Or Thor.
Can you believe we'll be seeing an Ant-Man movie before too long? And D̶̶C̶ WB can't even get a Wonder Woman movie off the ground.
Edit: No, you're right. I was thinking purely the 'Marvel Cinematic Universe', but the OP talks about all the other franchises too, so apologies for that. All that typing just to make myself look foolish.