First let’s establish a few things. Hollywood is not an equal opportunity employer, in any way, shape or form. Bound by antiquated ideas about what “the public” wants, and can accept, it regularly passes on POC actors for POC roles in favour of whitewashing them to gain “greater audience appeal”. As in publishing, Hollywood also engages in the behaviour of not supporting or heavily advertising material featuring POC cast as main characters as much as they do material that doesn’t.
The next thing to establish is that no, the incredibly rare occurrence of having a POC fill a role that would traditionally be white does not make up for, or equalize in any way, shape, or form, the continued efforts that Hollywood goes through to whitewash everything else. It’s important to point this out, because these same voices were utterly silent, or dismissive, when Ridley Scott released the thoroughly whitewashed Exodus: Gods and Kings, or when Darren Aronofsky released the equally whitewashed Noah.  However, this has not stopped people from pointing to the statistical outliers like Idris Elba as proof that criticizing Hollywood of being racist or of whitewashing films “isn’t fair” because one POC got cast in a role that they say should have been for a white actor.
So where is this all leading? Well, all the films I mentioned in the opening paragraph are currently subject to extreme criticism because they have either dared to think about, or have cast, POC in a role that part of the fandom sees as being exclusively white, or has been caught whitewashing and been called out on it.
Full disclosure, I am not a Spider-Man fan. At all. And no, nothing you can say or post will change this. Having laid that out there, there are currently two Spider-Man characters in Marvel Comics, and it has gotten racist, fast. In the regular Marvel Comic Universe, Peter Parker is Spider-Man. In the Ultimate Marvel Comic Universe, Peter Parker was killed, and has been replaced by Miles Morales, a mixed Latino-African American. As a result, given the Ultimate roots of the Marvel Cinematic Universe, it’s now entirely plausible to have a POC Spider-Man. This very idea has set the nerd herd on fire, and while many support it, the racism in the comments sections of articles on the topic are very telling in of themselves. This is an example of a POC character who could, very legitimately, be inserted into the growing Marvel movie franchises, but who a section of the fandom refuses to even acknowledge as being an option. As it stands introducing a POC Spider-Man in the Avengers franchise would make them the first POC in the cinematic Avengers line up, which is currently all white.
I should probably be honest, I’m not a Fantastic Four fan either. However, the casting decision to have a POC Johnny Storm and a white Sue Storm has again touched off a barrage of racism from part of the fan base. Whereas Mile Morales is an established (albeit in a parallel series), Johnny Storm has no such equivalent. Apparently to some, the idea of a mixed race family, or blended family, that produces a white and Black kid is too much.  This is something I’ve talked about in the past, about how things don’t “blend” genetically, but have a variety of possible outcomes when you mix things up. this isn’t a huge deviation, they’re still siblings, and they’re still the same characters. I severely doubt that Marvel will trot out a “jive talking homeboy” stereotype; it’ll still be Johnny Storm, he’s just a POC now. Again, this falls into a smart marketing maneuver for Marvel. The Fantastic Four needs a larger market appeal, and a minor change does the trick.
Star Wars Episode VII is something awaited for with both fear and excitement by Star Wars fans, even hyper-critical, WTF is this “Expanded Universe” crap, fans like myself. POC actor John Boyega has been cast, possibly in a lead role, as a Force sensitive Storm Trooper.  Again, the problem is with a small but vocal minority who have decided that Star Wars is an exclusively white domain (with an exception for Lando). In a rare case of an immediate and stronger counter narrative emerging, fans have come out overwhelmingly in favour of John Boyega’s being in the new Star Wars. It has lead to both comedy and serious discussions on the idea of the participation and existence (or absence of more often) of POC in science fiction. The conversation that this has sparked has been very positive and productive in the areas of analysing how POC are portrayed and featured in science fiction, and in how POC and Hollywood can improve the situation.
Now, Ghost in the Shell is a personal favourite of mine. I had the complete collection of comics and the even the terrible 90’s VHS movie of it. I greatly enjoyed the Stand Alone Complex series, and even the less action packed follow on series by Masamune Shirow. The property has been licensed for a live action film, and like now cancelled live action film Akira before it, and the regrettably released Airbender film, a white actress has been cast as the main character, Major Motoko Kusanagi.  The backlash has, if anything, been stronger and louder than the outcry against the tanked Akira project. This is most likely because where Akira has languished as a property, with only the original comics from the 80’s and the film from 1988, Ghost in the Shell has been a much more active property in recent years, and has garnered a larger and younger fandom than Akira has. This case is a sign of the continued deafness in Hollywood to the changing tastes and acceptance levels of the movie going population, which has shifted away from the “gold standard” ideas of the 1950’s that still dominate the boardrooms and planning sessions there.
So, what’s the take away here? Well, for one, the idea that POC can be cast in roles traditionally reserved for whites is not an “unfair” practice, because it is literally a statistical outlier situation. The only reason it’s become a rallying point for overt and closeted racists is because it’s happening on big ticket film projects. If these same voices were as strident about getting things right in the films where the cast is whitewashed, they might have some credibility, but in these cases they are always silent, or claim that it was the only way to get funding, or loudly proclaim that the actors and actresses were selected for being the “best choices for the role”. The latter of which is a defence that they reserve exclusively for white actors and actresses, and deny to POC ones. The worst defence levelled by these people though is a combination of the “slippery slope” and “reductio ad absurdum” logical fallacies. These being combined in the faulty argument that if you dare change one character’s ethnicity, that eventually all characters will have to be swapped. It’s also presented with a healthy amount of “I’m sick of all the political correctness [ruining my perfect white fantasies by including POC as equals or main characters]”, or the always fun “I’m not racist, but… [I hate seeing people who aren’t like me on the screen of the idea that things might change]”.
Things are changing, times are changing, and it’s not going to stop. POC are demanding to be allowed into the spaces that were denied to them in the past. And “separate but equal” is not an option, because it’s never equal. This isn’t an attempt to hijack every property and make them into POC. This is an awkward fight between an establishment that’s blundering forward as much as it tries to cling to the past, and a population that is demanding recognition. It’s also a internal conflict in the nerd world, as we fight to establish that we are allowed to be in these spaces, have the same rights to good portrayals, and that our voices are as valid and strong as any other reasonable person’s.