Back to the "Ladyhawke decades", here's a question: not many live filmmakers made good fantasy then. But was there much live SF that worked, if we factor out the existing Star Wars and Star Trek franchises? Does that still leave enough decent science fiction to make the case that Hollywood was more comfortable with it? (Or just thought the Star Wars craze applied to it better?)
I think you can find some good science fiction from the time period.
Alien
Aliens
Blade Runner
Scanners
Mad Max (I liked it, anyway)
Altered States
Terminator
Videodrome maybe. Weird one anyway.
Brazil
Remake of The Fly (liked it at the time, don't know how it held up)
Akira (not Hollywood, though)
I liked the first Total Recall, cheesy as it was.
The Thing
um...what else...
oh, freaking E.T.
There have to be more.