I’ve read quite a bit of Science fiction, and most authors have never seemed conservative in the least to me. Not that they necessarilly were overtly liberal, but collectivism and such were almost always promoted and individualism unimportant. To say the least.
It’s hard to write an interesting story about a collective.
The genre itself has to deal with individuals making choices and living with the consequences, which will to some extent causes stories to drift towards conservatism, even if they wouldn’t admit it.
Try Baen.com
They have have several authors that are wide right. Kratman considers himself to the right of Attila the Hun
I would recommend reading just about anything by Jack Vance. His themes are the opposite of what you describe.
You can read a ton of out of print scifi from Baen right on your computer. for free.
click on ‘The Books’ on the left sidebar to see the list.
Any group of profession writers will have a preponderance of leftists. That's the way it is.
But an awful lot of libertarians are or were SF nerds, so there's definitely something else going on in the genre. Any group that took -- and takes -- Robert Heinlein so much to heart, isn't uniformly liberal.
Science fiction is one place where individualistic ideas of doing without government and bureaucracy have taken root. That may not be conservative, but it certainly is libertarian.
But I wouldn't say that the SF world is getting more conservative. It's more that older liberal and radical ideas got stale. Fans will get bored with conservative or libertarian tendencies in time and look for something else.
That's probably why some writers latched on to global warming or climate change theories; not so much ideological commitment, as something new to write about.