Classic Sci-Fi and Character

I'm reading, or trying to read, a classic science fiction novel called The Drowned World by J. G. Ballard.

I'm still at it, but it's been pretty difficult.  It's a problem that I run into with nearly all the classic science fiction novels I try to read.  The characters in them seem to be so wooden and uninteresting that I can't give a crap about what's going on in the book.  Why is that?  I'm sure all the readers of this blog know better than me.

My guess is that a lot of the authors who wrote science fiction in the classic era were scientists first and writers second.  It's like they have an idea about something that could happen; like the earth heating up, causing the ice caps to melt and evolution to digress creatures back into a state that suits that environment; or a world that is like a ring around the sun, so it's a million miles wide and 600 million miles in circumference; and then they shoehorn in some sort of meager plot and characters.

I'm trying not to give up on the book, but I have no reason to keep at it, really.  Stephen King once said that if an author hasn't hooked you by the 15% mark, then you have no reason to keep reading.  I'm past that, but I'm slogging on.  Any time I've done that in the past, I've found that it was the wrong decision.  I never grew to appreciate the story later.  We'll see how much longer I can go.