//why can't weee be friends//
Just kidding, we are friends ^_^ there's some definite competition between Marvel and DC, and I think that the spirit of competition trickles down to fans from time to time. Which sometimes can be a lot of fun! Sometimes competition drives writers to achieve more- someone sets the bar high and then everyone else works to do even better. I think as long as fans emulate that example there's no reason why we can't all live in harmony.
Here's some unusual animal friendships to prove my point:
I'm not crying you're crying.