3. Fan-Casting Has Been Proven Wrong Too Many Times
This reason is sort of a cheat as it doesn't have as much to with Affleck as it does with fans in general, but has Heath Ledger taught us nothing? When Heath Ledger was cast as the Joker in The Dark Knight (greatest superhero film ever made), hissy-fits were thrown by the millions. There were the obvious, simple-minded bigots who didn't want their beloved Joker portrayed by the same man who was nominated for an Oscar for playing a gay cowboy. There were those who only thought of him as a heartthrob type much as many did (and still do in certain cases) Affleck. There were those who had there own ideas of who should play the Clown Prince of Crime (looking your way, Hugo Weaving). There were those who didn't dig the first promo shot of Ledger almost deliberately not smiling, as if he wouldn't be smiling in the film, as if someone smiling was all that was required to play the character. Every single one of those objections were written down, thrown in the dumpster, and set on fire once the first, real trailer for the film was released. Once actual footage of Ledger as the Joker was seen by the public, everyone who objected immediately shut up. Why? Because once again, the fan community jumped to conclusions that were based entirely on conjecture and nonsense. Being an Academy Award nominee wasn't enough to get Ledger at least a "we'll see". They had to actually see it and when they did, do you know what the Ledger defenders asked? "Did Michael Keaton teach us nothing?" Listen, Zack Snyder cast Henry Cavill as Superman. That seemed to work out okay, right? So, can we give the two-time Academy Award winning, experienced actor who was cast by the same guy who cast Man of Steel full of great actors at least a "we'll see"? Obviously, you can have your doubts, but given the history of knee-jerk reactions to superhero film casting in the past, is it too much to reserve judgement until actual footage is released? I fear, for many, it is.