Crichton's later works had that effect on me, too.

For me it was the contrast between what I'm looking for in a SciFi book and what Crichton writes. I like SciFi that asks an interesting question and then tries to (speculatively) answer it. What would the world be like if <X> was different?

Crichton pretty clearly adopted a pattern of "OMG THIS TOPIC IS A DISASTER!!1!!1!! READ THIS THRILLER TO SEE THE DISASTER!!11!!". I exaggerate, but not by much. At some point each of his novels had a theme, and each theme was some well-written disaster porn. What if genetics goes awry (Jurassic Park)? What if nanotech goes awry? Etc, etc.

Which was sad for me - he was a good writer, and I enjoy reading his novels. It's just not what I'm looking for anymore.