Some of this is dependent on genre definitions and I have a love/hate relationship with genre labels. As a librarian, I appreciate them and how they help patrons find books they want, which really means within their comfort level. They find something they like, they want more like it and that usually means similar subjects or themes or settings and that usually means genre. Other readers are more adventurous.
For 15 years, I read almost exclusively what most people would consider science fiction. I purposefully stuck to the science fiction section of bookstores, working my way through authors I liked, and books that sounded cool. I liked the variety within the genre. I'd read social science one week, a space opera the next, followed by some time travel, alternate universe or alternate history, a bit of cyberpunk, then maybe something in the hard sciences. Occasionally, a fantasy would slip in. But still, my genre reading was at the mercy of the publishers who stuck "science fiction" on the spines of those pbs and the bookstores who shelved them there. These days, a science fiction book could have Fiction on its spine and be shelved in general fiction unless the bookseller knows enough to put it in SF. And plenty of quasi-SF writer get shelved there because the booksellers think they'll sell better there. Or maybe they'll shelve in both places, something libraries can't do.
On the other hand, I know the label is pretty much a marketing thing. I know it's subjective. I know the various definitions of SF and Fantasy and what supposedly differentiates them from each other and all the other books. "Science fiction is what we point to and say is science fiction." Could it get any clearer? Could it get any more confusing?
I know people consider Michael Crichton a science fiction writer, at least for some of his books. Hey, they have science or pseudo-science in them, what else could they be? But I've never seen them that way. They're adventures, thrillers. The setting is simply window dressing. Is Crichton a great writer? I don't think so, but I know a lot of readers who would say yes. He sells well, so he clearly has hit on something people like, enough people to make him a bestselling author. I would never disparage that because, to me, to do so would be to disparage his fans, too. And I did enjoy both Jurassic Park and Timeline despite their flaws, flaws the average reader not well versed in science and/or science fiction might not catch. In no way do I think that makes Crichton a sloppy or shoddy writer. Maybe over the years, he's skated a bit, but I won't sneeze at good enough, either, not if it can be successful. When you reach his level of sales, you get that kind of clout. But then, I don't know if he's skating or not. I know only if a book feels that way to me.
What I do know is that I enjoyed the two Crichton books I read more than the SF book by a hot, new SF writer critics have been falling over to praise. I found the book difficult to follow and the characters failed to engage me. Does that make the book a bad one? No. Just a book that wasn't for me.