@boomerang,
These are good points. Michael Crichton originally published under the name John Lange, and was a practicing physician at the time--apparently, he thought being a novelists was inconsistent with the
gravitas of the medical profession in the 1960's. One of his novels, about an abortion (very hot topic in the late 60s) was such a critical success that he began publishing under his own name (the novel,
A Case of Need, was re-published in 1993 under Crichton's own name), and
The Andromeda Strain was enough of a success that he could give up the practice of medicine to write full time. He wrote an awful lot of BS, but he's a good story teller, so i forgive him.
One's tastes change over time, too. In the last few years, i've re-read several novels, and series of novels by certain authors. I've re-read several of the novels by David Cornwell (writes under the pen name John le Carré), and have been less impressed than i had been in the past, especially as i read them one after another recently. There is a narrative technique of his which i find annoying. He will drop into his narrative a remark such as "later, it was said that Smiley . . . " or, ". . . at Sarrat, they said that Smiley . . . " I find it tedious and just wish he'd get on with the story. Joseph Conrad employs the technique much more successfully. He has a character, Charles Marlow, who narrates several of his stories and novels; Marlow is the central character in
Youth--it is his youth he is recounting. Most readers will have encountered Marlow as the narrator of
Lord Jim. But Conrad introduces Marlow and other characters, and then lets Marlow get on with the narration. I dislike Cornwell's habit of dropping such remarks into the story line.
I first noticed this in my early 30s when i re-read
Starship Trooper. It just wasn't the novel i recalled. Then i re-read
Farnham's Freehold, and was frankly disgusted by Heinlein. He is elitist, racist, sexist and "agist" (only middle aged or old men really know the score). He's a good story teller, and i will forgive much for that. But if i find a Heinlein novel i haven't read, i can get through it pretty quickly. My eyes start to glaze over when i get to one of his long passages of preaching the gospel of his version of libertarianism, so i skip through to where the story resumes. Saves me the trouble of reading about half the book.
There can be other factors, too. There is an idea called the Fermi paradox. Without going into detail, it's a load of old horsie poop. However, the consideration of it lead me to question the basis of most science fiction. So much of it depends on avoiding the implications of the speed of light, so that authors either present a pretext for fast travel in the galaxy (as Herbert does in his
Dune novels), or they simply just assume it. That's fantasy, not science fiction. Marion Zimmer Bradley, in several of the prefaces to her books about Darkover describes her writing as science fantasy. I appreciate the honesty, and can proceed to enjoy a good story teller. I've only read a few good science fiction works which i felt did not stray into fantasy. Those are the Mars novels (
Red Mars, Green Mars and
Blue Mars) and
The Forever War by Joe Haldeman. The Mars series does no violence to science, and is fascinating within those reasonable constraints.
The Forever War, which won the Nugo award one year and the Nebula award the following year, does what science fiction does best, examining social and moral issues. It does it with an interesting twist. The soldiers in this war, male and female, are transported to their bases or to attack enemy bases, at relativistic speeds. In the end, the forever war lasts 1200 years--but the soldiers who survive had only aged about 25 years. A great read which i highly recommend.
Some authors stand up well to such re-reading scrutiny. I continee to enjoy Marion Zimmer Bradley and P. D. James. Others fail that test--David Cornwell, Tom Robbins and John Irving, to name but a few.
The upshot is, though, that there is just no pastime quite as rich and rewarding as reading.