Sci-fi writers are not open to all views, or with an advanced perspective on things. Sci-fi writers are often the exact opposite. Sci-fi allows one to make a specific argument obvious when it is not so much so in the actual world. Or make an argument that is actually invalid in reality, but works due to the parameters of the fictional world.
And the temptation to do so is usually all too great. A human has a divine nature through his desire to understand. How do we know this? Because Valentine Michael Smith has shown us thou art God. Except he doesn't exist, and no one can actually do what he does, no matter how much they grok the universe.
There is no just war; we should forgive even those who try to kill us to the last. How do we know this? Because an alliance with the Cylons is the only way to locate Earth and rebuild humanity. Except we're not looking for Earth and we're not at war with Cylons, nor with anyone with whom interbreeding holds some huge mystic significance about the Shape Of Things To Come.
Humanity is fallen, disconnected from something greater, and needs to reconnect with God. How do we know this? Because Elwin Ransom learned it on the unfallen Malacandra after meeting its people and its Oyarsa. Except we have yet to encounter another inhabited world, fallen or unfallen.
We must protect the earth at all costs, because preserving its Mako is the only thing keeping it from literally falling to pieces. We must not hate other races, because the dwarf and troll leaders wanted unity before they were lost in a cave-in. We must not try to seek an orderly utopia, because it'll cause 99.9% of a planet to give up on living and the rest to go viciously insane. We must not cheat death because... well, I could go on for days naming all the fictional reasons we mustn't do that.
If our world made it obvious what the answer was, we wouldn't be asking the questions. But once someone has engineered a world with rules to their liking, they can answer conclusively "why" their view is the only accurate one. "Because look at my story! Look what happens there when they follow my viewpoint, and when they don't!" And if no one points out the fallacy -- "yeah, if your story world were real, that would be the case, but that's a big IF" -- then they find themselves certain. Clearly, their view is the only obvious one. Their world tells them so. They need not justify it any other way.
Even if the view happens to be accurate, or at least possible, relying purely on the story is pointless. It proves nothing, and makes one weak in actual arguments. Argumentum ad fabula: argument from fiction.
Which brings us to the readers. A reader who focuses on one author is not only going to get the same conclusions, but is all the more likely to forget that hey, this isn't an ethical textbook you're reading. But that assumes one author. What if you read of CS Lewis's divine eldils and Robert A. Heinlein's divine man? What if you see the utopia of the orderly Federation in Star Trek and the dystopia of the orderly Alliance in Firefly? What if you still consider multiple options, what if you remember that sci-fi describes what might be instead of what is, in multiple senses of the phrase? What if you think for yourself which makes more sense given the world you yourself know? Well, that's what makes sci-fi readers open to more views...