Focussed is fine, and LTS support is important… But right now there’s a very real and pressing need to be able to simply compile projects without errors and without tedious management of multiple JDK versions when the user has JDK9 installed.
For the record, Scala team has been working on JDK 9 support (for example https://github.com/sbt/sbt/pull/2951 was sent Feb 2017, Scala 2.12.4, 2.11.12, 2.10.7, and sbt 0.13.17 were released to add JDK 9 compatibility, etc). And we want to make sure people can build things in JDK 9.
This is doubly true given the EOL status of JDK 8
JDK 9 is going to be EOL next month (March, 2018). JDK 8 is planned for EOL September, 2018.
All that’s needed right now is a simple way to specify the import of those modules that used to be in the standard library under JDK 8 and earlier.
Specifically for Java EE modules like JAXB, isn’t the proper migration just adding appropriate
libraryDepedendencies according to Migrating to JDK 9?
If there is a specific thing that’s blocking you from using JDK 9, could you open a GitHub issue for it or comment in https://github.com/scala/scala-dev/issues/139 please?