The situation is quite complex. A big part of the industry seems to be stuck at Java 8 right now due to several reasons. One of them is the momentum Java 8 gained when it was released in 2017, 8 years after Java 7. It was a strong release, bringing much-awaited features to the aging Java ecosystem. Subsequent released didn't come anywhere close to that.
Another big reason is the uncertainty of the upgrade path. Java 9 was released comparatively short time afterwards, and it is set to expire... last month. [1] Unsurprisingly, many customers chose to stay with a stabilized, thoroughly tested version of Java 8, rather than switch to a bleeding edge (in Java terms, at least), untested Java 9 with a very short time fuse on it. Finally, Java 10, which has been released recently, is also due to expire very shortly - in fall 2018.
So overall this looks like a very aggressive monetization move on Oracle's part, intended to extract $$ from customers who value stability of their platform. It goes completely against the long-established tradition of stability in the Java ecosystem, which is one of the reasons many of the customers chose it, in the first place. I expect a massive migration towards OpenJDK and a backlash in the community, which will ultimately push Oracle aside.