Lovecraft remains an underrated sci-fi pioneer as well as a horror writer. His depictions of the alien are notable for being truly alien. A lot of his "eldritch horrors" weren't necessarily evil so much as so alien that their value systems, motives, and conception of morality are incomprehensible to human beings. This might well be the case if we meet real aliens. We'd be able to converse about objective things like math and physics but beyond that we might find our worldviews to be different to the point of near mutual incomprehensibility.
A lot of later sci-fi actually retreated to more human-like familiar notions of the alien. Very few sci-fi works have explored Lovecraftian aliens -- maybe Arrival (notable for the aliens being benevolent but Lovecraftian), The Expanse (though the alien machines use simulated human minds to talk to us, making them seem familiar), Alien (the Xenomorph), and a few others. Edit: the Blindsight series by Peter Watts is another.
The Alien franchise is a huge missed opportunity for failing to develop the Xenomorph as an alien race. I always thought it'd be neat if they turned out to be intelligent insect-like hive-mind aliens that just don't realize they're doing anything "bad" because they don't understand our concept of individuality. In their environment using some of the drones of another hive to reproduce would be fine, even a kind of social interaction, so when they do it to us think they're saying hello. Their apparent violence is just the ultra-utilitarian behavior of drones. Ripley's comment in Aliens about "I don't know which one is worse" might have been a hook for that. We might have eventually learned that our sociopaths were, in fact, quite a bit more "evil" than the xenomorphs, who are just very unlike us biologically.
I'm aware of some of Lovecraft's personal shitty views, but I think it's unfair to judge people from another time by the standards of this age. His views would not have been unusual for his place and time, and they only really show up at the edges of his works anyway. I read all his works and never really picked up on those subtexts until it was pointed out to me later.
There was a long period of time where he _was_ ignored and underrated, up until 1981, when Stephen King gave him a shoutout in his book about horror writing (Danse Macabre) and the Call of Cthulhu RPG was published. Until then, his books were entirely an underground phenomenon, and even then it wasn't until the early 2000s or late 1990s that Cthulhu was anything but a shibboleth for ultra-nerds.
He was sort of a perfect fit for the generation of kids raised on computer games and RPGs that had voracious appetites for new mythologies.
It is funny how once you get tagged with "underrated" it just stays with you forever, though.
Underrated? No. Underdiscussed or undertaught, yes. His overt racism makes open discussion difficult. But anyone who reads horror seriously very much appreciates his work.
It is possibly a religious thing. The puritan/protestant influence on american culture tends towards down-to-earth fiction that avoids discussion of fantastic situations that rub up against religion. Lovecraft's basic mythology is that there are things older than the earth. That conflicts with creationism and so would be a shunned in 18/19th century america. Such things certainly would not be found in school libraries.
The old people here might remember the anti-magic push in the 90s, the satanic panics and efforts to stop Halloween. Midi-chlorians were part of this, removing magic in place of scientific explanations. Then harry potter swept the movement away.
AIUI France took sci-fi somewhat more seriously than the anglosphere did from earlier on (maybe due to Verne?); in English-speaking countries it was really seen as pure genre fiction with negligible literary merit until quite recently.
A lot of later sci-fi actually retreated to more human-like familiar notions of the alien. Very few sci-fi works have explored Lovecraftian aliens -- maybe Arrival (notable for the aliens being benevolent but Lovecraftian), The Expanse (though the alien machines use simulated human minds to talk to us, making them seem familiar), Alien (the Xenomorph), and a few others. Edit: the Blindsight series by Peter Watts is another.
The Alien franchise is a huge missed opportunity for failing to develop the Xenomorph as an alien race. I always thought it'd be neat if they turned out to be intelligent insect-like hive-mind aliens that just don't realize they're doing anything "bad" because they don't understand our concept of individuality. In their environment using some of the drones of another hive to reproduce would be fine, even a kind of social interaction, so when they do it to us think they're saying hello. Their apparent violence is just the ultra-utilitarian behavior of drones. Ripley's comment in Aliens about "I don't know which one is worse" might have been a hook for that. We might have eventually learned that our sociopaths were, in fact, quite a bit more "evil" than the xenomorphs, who are just very unlike us biologically.
I'm aware of some of Lovecraft's personal shitty views, but I think it's unfair to judge people from another time by the standards of this age. His views would not have been unusual for his place and time, and they only really show up at the edges of his works anyway. I read all his works and never really picked up on those subtexts until it was pointed out to me later.