Not long ago, I noted to a friend how certain people with engineering and math backgrounds seem peculiarly susceptible to fringe theorizing of the most stomach-turning sort: crackpot history, conspiracy theory, antisemitism, the whole rotten tamale. What is it that takes someone who really ought to know better and turns them into a dolt blithering nonsense that withers under thirty seconds of critical thinking?
For those not familiar with the term, that's the name for an effect where people routinely overstate their competence in a given area. It happens to different people for different reasons, and the reason it seems to happen to math, engineering, and science types is because they don't believe they're deluded. They think that by dint of being an expert in one field, that translates to expertise in other fields, even if the expertise in question maps not at all to another discipline. Hence, a professor of electrical engineering who fancies himself to also be an expert on WWII history, or a gifted and otherwise brilliant professor of math who falls down the rabbit hole of 9/11 trutherism. (I won't name names.)
Or a science fiction author who believes the HIV virus doesn't cause AIDS , or doesn't think AIDS even exists as such.
(Please note this is a hypothetical example. I had others, from the real world, that were far worse.)
I don't think SF authors — or authors in general — have an obligation to be scientific authorities, but I do think they have an obligation to be scientifically literate. Maybe better to say they have an obligation to be literate in the ways evidence is amassed and assessed. If they want to seriously entertain the idea that HIV doesn't cause AIDS, or that global warming is not the result of human activity (or is wildly overstated, or what have you), then they have an obligation to know if their sources are genuine scientific ones. They have an obligation not to cite crackpots and ballot-stuffers for their evidence, and to make an effort to not assume that dissent automatically equals truth. They have an obligation to adhere to the same standards as the very scientists they claim to venerate, to let themselves be proven wrong and be good sports about it.
I don't believe for a second that all SF has to rely on airtight science. That's why they call it science fiction. But no art exists in a void of absolute aesthetics. If you write a story where, say, you seriously entertain the idea that AIDS is not caused by HIV, you have to know that your audience for that story exists in a world where AIDS is most definitely caused by HIV, and where crackpot AIDS denialism kills people. You have to know that the reception for such a story isn't going to be terribly sanguine, and that most of the people who cotton to it are likely to also be people who warm up to some flavor of crackpot thinking.
Most of the arguments in favor of what could be called free speech purism are rather angrily contrary about this fact. A person should be able to say what's on their mind, to challenge the orthodoxies of the day, and all that. Fine. I believe such things myself. I don't believe they permit you to make up your own facts, and I definitely don't believe they grant you immunity from the consequences of propagating them. If you write a story that sides with some view of human reality that is, well, inhumane, are you really shocked that someone might call you on it?
Thing is, I doubt most of the people who express appalling viewpoints with a straight face, whether in fiction or out of it, believe what they do is appalling or worthy of censure. They think they're doing the proper thing, which is standing by what they believe to be right. To me, that only serves as further evidence such a strident, pompous certitude is the sign of a dead mind. I would sooner see someone change their minds a dozen times and be wrong half the time, than see someone change their mind never and be always wrong. At least the first guy has a chance to get it right.