They're two separate world's. Marvel is sappy. DC is gritty. Marvel characters are basically human. DC characters are basically gods. Marvel, even when it decides to tale a walk on the dark side, always keeps that lighthearted, goofy feel. DC is a straight face through and through. Marvel makes the whole universe seem like a playground, even when it portrays cataclysmic events, as in GotG. DC acknowledges and emphasises the notion that the universe could really give a crap about the beings in it. Different views. Different opinions. No rivalry.