I know where you're coming from, and I agree a lot of it is an age factor.
Don't get me wrong. I don't mean to indicate that age is the only factor. There are other things that would factor into that kind of mindset like general awareness, interest level, and of course, personal preference.
Look, we've disagreed on this issue before, but I really don't think it's accurate to say it's just some tiny minority of nerds that engage in this kind of thing. In today's rampant geek culture (which at this point is really just a synonym for pop culture), this kind of stuff gets talked about all over the place, all the time. You have fan community "spokesmen" like John Campea making statements like Batfleck "makes Bale look like a teletubby". And honestly it's fine, it's part of the "getting hyped for the new version" process. I agree with Annefan that this version will be able to stand the test of time in the end, but for better or worse that perception is out there and it's being fed.
I also never suggested that there is only a tiny minority of people who care about films like these. However, you and I both know that the majority of people who watch these films are not nearly as invested in the films or these characters as we are.
We spend just about every day writing and communicating about these films, analyzing and exhausting every aspect of them (including facial stubble). We are exposed to hundreds of vocal opinions daily about previous films, films that are in production, and films that are planned sometimes 5-10 years into the future. We are also exposed to people who have clear biases against certain films, interpretations, characters, actors, and studios. We are knee-deep in the hype and anticipation that often causes people to make irrational statements or claims, or to lose sight of what's come before.
My point was that yes, we will see people write of Bale's Batman in favor of Affleck's, just as we saw people write off Burton's Batman in favor of Bale's. But while hardcore fanbases can seem quick to flip-flop and turn on previous iterations or actors, I don't think the same can be said for the majority of people in the world who will flock to theaters to see BvS. It's silly to think that a huge chunk of the people who see that movie will walk out having turned on TDKT and writing off that version of Batman as crap.
I once wrote that I don't think being a comic book fan can be considered "geeky" anymore, because superhero media has become ingrained into pop culture and is now widely accepted and anticipated by mainstream audiences, so I agree with you on that front. That doesn't change the fact that there is a vocal portion of the fanbase that loves to make their opinions known, and that communities like the Hype are not truly accurate reflections of how the world feels about these films.
Also, anyone who considers John Campea to be the "fan community spokesman" is an idiot. He is exactly the kind of vocal, irrational, and biased fan I'm talking about.
I think Bale being overlooked in the best movie of his Bat-franchise (and arguably his career) could be emblematic to his place in the character's history. His movies might be among the most well-revered, but it's very possible he'll end up kind of as the "Timothy Dalton" of Batman. A more serious, grounded version, but far from the most popular (though at the same time ridiculed for the voice). I'm fine with that, and if that's what happens then so be it. Who knows what will ultimately happen once Batfleck is fully unveiled to the world, but I don't think it's an outlandish prediction, at this point that's where the smart money is.
I completely disagree, and I think you're looking a that from a "worst case scenario" perspective. It also seems like you're underestimating just how popular and well received those films were, along with their ability to stand the test of time.
The only "Timothy Daltons" of the Batman franchises are Val Kilmer and George Clooney. In the past 10 years, the only two Batman actors that seem to get any recognition from fans and the media are Keaton and Bale, rightfully so. Christian Bale was Batman in a trilogy of films that were acclaimed by fans, critics, and audiences alike -- the only Batman actor to do so thus far and the only series that chronicles Batman from his beginning to his end.
Most now consider a movie like Batman 89 to be a classic, 25 years later. The Dark Knight is already to be considered a classic, and if you give it time, I think you'll see that Bale's Batman and the trilogy as a whole will be considered the same. It might not wind up being the most popular version of Batman in 50 years after 5 more actors take up the mantle, but it will always be remembered, respected, and appreciated as a part of Batman's long, never-ending history. That much I know for sure.
I think the fact that WB are "jumping right in" with the new Batman rather than rebooting from square one again so soon (a la Spidey) will only serve to help TDKT stand on it's own and be remembered for what it was.