Why are a lot of DC movie fans so unwilling to hear criticism of their WB's films?

I'm a DC movie fan (the original Superman and Tim Burton's Batman are still favorites of mine), and I'm willing to listen to whatever worries people might have about the DC Cinematic Universe. I don't have any idea whether they're going to "kick Marvel's ass" or "stand the test of time because they mean something more than whatever Marvel's doing", because I haven't seen their movies. I have hope that it will be good movies, because a lot of talented people are involved with the project (thought I have my doubts about Zack Snyder and David Goyer).