Let preface this by saying that I am a 40yo American male of Puerto Rican descent. That said, Rodriguez had a valid point and shouldn't be strung up for saying it.
I'm all for color blind casting, but only where appropriate. Comics are different from books or plays. They're a visual medium whose stories are often told over decades. A character like Batman well predates even my own ~70yo parents. Because he's endured for so long, Batman has become iconic. If one were to cast, for example, a 5-ft tall Chinese guy instead of a 6-ft tall white guy as Batman then people would complain.
Because comics are a visual medium... Because these characters have been around for so long... We have a clear and well established idea what he's supposed to look and act like. Batman looks like "x" and anybody cast in the role would have to come as close as realistically possible - within reason.
Suggesting that Batman should only be played by a tall, young, & muscular white guy isn't being racist, ageist, or sexist. It's being faithful to the source material. For the comic companies, that's not such a bad thing. Imagine never having heard of Batman before. Now, suppose that the first time you see him is when he's played in a movie by somebody like Terry Cruz. That in itself could be pretty bad-@$$. However, imagine going to the comic store right after to hunt down every Batman comic you could find. Wait a second?!? Who's this guy? Why is Batman suddenly white? That's not MY Batman.
From the publisher's perspective, there's a case to be made for synergy.
Most moviegoers aren't comic readers. I recognize that. Their connection to these characters isn't the same. That said, it's still an issue of source material fidelity.
I get the complaint of, "I'm sick of there being so many white guy superheroes at the box office." I go to the theater and I don't see a Hispanic superhero lighting up the box office. I turn on the TV and it's the same thing. Do I blame the production companies for not color blind casting? No. They're just trying to stick to the material. Do I blame the comic companies? No. They're doing their best.
I blame history.
The characters hitting our screens just so happen to have been created in an age where white guys were only creating white guy characters. It's just what they did back then. Women got screwed too. It's not just a minority issue. Most of the iconic characters, save for the occasional Wonder Woman, are white dudes. Because these are the enduring icons, that's why we see so many white faces during our super hero summers. There are newer, more diverse characters that were created in a more enlightened age, but they are generally not as iconic. Yet.
I go to NYCC every year. Every year, at some panel, I hear the same question. "When are we going to get more minority or female characters?" The answer is generally the same. "We're creating them all of the time. Just open your wallet and open our books."
Companies like DC and Marvel work VERY hard at making their universes more diverse. New characters of all ages, ethnicities, genders, religions, and orientations are created all of the time. Marvel & DC create these characters and rarely do much in the way of "recasting" the old faves just to be PC. (Sometimes they do, but not to any lasting effect.)
There's no need to be PC and recast the icons. We can leave our old timey white dude characters intact. If you want to see more minority superheroes on the big screen then you have to start supporting those characters at the comic book stores. If they see that there's a huge demand for characters like Ms. Marvel or Cyborg then we'll see these characters appear more in mainstream media.
I accept that Superman & Batman are white or that Joker or Wonder Woman will never be gender swapped on the big screen. I'm fine with that. They are the products of their time. I wouldn't have them any other way.
Maybe we should be asking movie studios NOT to gender/race swap characters, but to spotlight the quality female & minority characters already out there. More Ms. Marvel. More Luke Cage. More Black Panther. More She-Hulk. Hell, even more Squirrel Girl.
There ARE quality characters out there who fit the diversity bill. Use them. There are new ones being created all of the time too. Use those too.
Hollywood's afraid to move beyond the safe bet. They're afraid to stray too far away from the established icons. They're afraid to risk it all on newer properties. I get that. It's not solving the problem though.
Like I said.... Support those minorty & female characters at the store level. Create a demand for them to get translated elsewhere. The problem's already being solved daily on the creator side. It's our turn to do something. Let's not shift blame or demand outrageous solutions to problems that are already fixed or in the process of being fixed.