It is absolutely science fiction. (Lots of technological advances in sf got explained in less detail than here.) The story ran in F&SF, after all. But it goes against the gosh wow stuff that some people think characterize science fiction, and it is one single advance that does not affect anything else.
I know it is not considered as sf by the general public because Cliff Robertson got an Oscar for playing Charley - and when did that happen in an sf movie people think of as an sf movie?
I had a SF author/professor once define science fiction by the Maguffin: there had to be some scientific concept/object/event/entity that was beyond current thinking/capability, and which figured centrally in motivating characters. That’s worked pretty well for me ever since.
There are a few more, but not many. The XCom videogame series has laser weapons in it; the excellent and very sober children’s book Whales on Stilts features an army of whales that invade the eastern shoreline with the aid of giant stilts, mind-control caps, and bionic laser-eyes. But wait, I guess this last one isn’t really a laser gun, so it doesn’t count.
I don’t think it would be. The science is never explained to us, it’s true. That’s the case in most science fiction. But the important part, the part that makes it science, is that, within the story, it’s explainable. And that’s absolutely essential to Flowers for Algernon: If it were an unexplainable magic spell, then Charlie wouldn’t be able to study the process himself once he became smart, and realize that it couldn’t last.
Now, there are other sorts of science fiction. Niven’s “Inconstant Moon”, for instance, has no technology whatsoever beyond what we have today, and the technology of Asimov’s “Nightfall” is behind ours in a few critical areas. In both cases, the driving force of the story is a purely natural phenomenon. But again, in both cases, the natural phenomenon is one which in principle can be, and in fact largely is, understood by the main characters.
Real Genius had an aircraft-mounted laser gun. There’s also that episode of Star Trek TNG where the crew is tricked into fighting a race that still uses laser-based weapon systems on their ships, which are entirely ineffective against the Enterprise. The Death Star used a “super-laser” to blow up planets. Lasers are a common short-range/point-defense weapon in the Honor Harrington books, and bomb-pumped laser warheads are pretty ubiquitous for longer ranges. The first Resident Evil movie had that laser grid that carved people into sections. The final assault on the space station in Moonraker featured one of the least convincing laser battles ever caught on film. Austin Powers, of course, featured sharks with frikkin’ laser beams on their heads. At one point in Akira, government troops trying to stop the rampaging Tetsuo deploy man-portable laser guns against him, to little effect.
You could say that about anything you could name, and it wouldn’t be true with any of them, either.
I understand fantasy and why some people are attracted to it. I am not a part of it. I consider it ridiculous, boring and a plot by the world shadow government to eradicate critical thinking and turn the population of the world into pod people.
With the exception of A Hitchhikers Guide to the Universe, which, arguably, isn’t fantasy or even SF, any more than Gulliver’s Travels is. Or if I was paid a million dollars to be the voice of a dragon.
But science fiction is just a subset of fantasy. Is has a “scientific*” explanation of the events, but the story is rarely about the science anyway.
*And in many cases, the science is nonsense and was known to be nonsense at the time the story was written.
I’m picking up on a bit of a contradiction, here.
This is of course arguable. It is not successfully arguable.
Too much like Margaret Atwood’s infamous comment that Oryx and Crake wasn’t science fiction because it didn’t have any “talking squids in outer space.”
Yeah, we get it. But you can’t win that argument. It just makes you look like a snobbish nincompoop. Atwood had to back off eventually. F&SF is a large, open container. It scoops up everything. You can’t stop it, you can’t deny it. It’s bigger than you are.
Sounds like you like fantasy just fine.
Consider The Road:
Other than unreadable, what are we supposed to consider it?
What is this “Hitchhiker’s Guide to the Universe” of which you speak? How harmless is it?
Don’t forget the lasguns in Dune.
Actually, as I recall, the issue in that movie was the lack of sharks with frikkin’ laser beams on their heads. Ill-tempered sea bass were a somewhat inadequate replacement, and Number Two never gets to say if the ill-tempered sea bass have laser beams or not. 
Gal-ax-y!
Well, excuuuse me, but I seem to be taking away an entirely different sense from this sentence by Harari, one which I entirely agree with. The thing that irks me about much science fiction is that the people who are described as living in the far future and ‘enjoying superior technology’ are also described as being *Homo sapiens *-identical to us. Of all the possible futures, I think this is the most unlikely. Once we achieve the sort of ‘superior technology’ that is the background for many science fiction stories- interstellar flight, powerful, portable beam weapons, etcetera, etcetera, we will also have developed equally advanced biotechnology and neurotechnology - in short we won’t be "Sapiens -identical to us’ any more. I’m pretty sure that this is the point Harari is attempting to make.
Take the various crews of the Starship enterprise. Most of them (even the aliens) were pretty much vanilla humans; more-or-less the only exceptions are Lt Comm Data and that hologram doctor bloke. It was fairly radical back in the Sixties to show black and white and Russians and Americans interacting as equals and friends, so kudos to them; but if humans are ever going to travel to other star systems, they will most probably travel as digitised DNA information or psychological recordings inside artificial bodies, not as farm-boys from Iowa.
Why is this a problem? Would you class the Homo sapiens who only used fire and stone tools as not identical to us
I don’t see that the one necessarily follows from the other (see Turtledove’s The Road Not Taken for a lovely deconstruction of this idea of all tech having equal evolution rates.) but I get the general thrust of this. I don’t see how that makes us any less H. sapiens any more than having smart phones does. Obviously, if the biotech gets to the point that the modified people can’t even breed with the baseline humans, then that would count. But just having cyberware and gene mods wouldn’t cut it. It’d take more radical changes than that (which could happen, I agree) enough that we don’t even think like we do now.
Seems like it, yeah. But that’s not really relevant to the issue of whether that’s a correct impression of SciFi. There’s lots of sci Fi that does deal with posthumans. I don’t think it’s enough to negate the “most”, but it does get addressed.
Star Trek does actually deal with the idea of why they’re all vanilla humans, both in the original Series and the second movie. You know, the Eugenics Wars…
Pretentious, depressing, scientifically and socially implausible, and over rated?
Meh, whatever. I picked it up on a whim, and stayed up late to finish it in one sitting. It might not be your cup of tea, but I thought it was the best post-apocalypse novel I’ve ever read, and I say that as a fan of the subgenre.
Of course, a lot of people find me pretentious, depressing, and scientifically implausible too.
That is kind of the point. Most SF assumes that human nature won’t change; this is understandable, because there is not much of a market for stories about beings that are radically different from ourselves.
I haven’t read the book, but I get the impression that Harari is looking forward to the future, to consider the next developments in human evolution; the sort of thing you’d put at the end of a book about human development so far. These future developments are likely to involve posthumans of one kind or another, or quite possibly several or innumerable kinds. Directed evolution will alter every aspect of our civilisation, and probably this will happen long before we reach the nearest star.
Unless of course our civilisation does collapse like a deck of cards, leading to the post-apocalyptic futures some people seem to relish. Or one might imagine a Butlerian Jihad or the Eugenics wars mentioned earlier - but such things would only delay the inevitable, rather than postpone it indefinitely.