I really like the idea of being able to compile java down to native targets.
Having a GPL compiler capable of that seems like a significant step forward - coming from a background of writing the deployment software for a much larger and heavyweight application, it would've been very nice to be able to break the JVM compatibility requirement and go native on arbitrary versions.
Then I see things like this: https://medium.com/graalvm/safe-and-sandboxed-execution-of-n....
Really nice features that will never make it into the GPL version, and it reminds me - there is always a price for Oracle.