"What I don't understand is why they didn't just make Java/JavaFX a center piece of this approach. I find it so ridiculous that companies always go about reinventing the wheel over and over."
I guess you simply do not understand the difference between Java and Native Code. The first is inherently (because of the memory model of the JVM) inefficient in terms of runtime and memory consumption. Realtime responsiveness can't be assured by Java (except if you use it in a strange way (no new statements after startup)) .
I guess you know what can be done by C/C++ based games, photo/video editing applications, CAD systems or relational databases. Native Languages like C/C++, Pascal, Fortran or Ada allow good programmers to write efficient, small and realtime-capable programs.
Google knows the difference between Native and Java(or .Net) while the drones of SUN (McNealy et al) were only able to generate excellent media spin.
You know, SUN is the "Stanford University Network". Don't expect academics to create something that is useful in the real world. What they do is a proof-of-concept and Java is no exception.