If you want to write cross platform desktop apps, your choices are pretty much either Java, C++ and Python. Rest of the languages/platform either don't have great library support or simply not mature enough to deploy at scale. Now if you want some performance, more mature UX library and eliminate Python, you are limited to C++ and Java. Its much more harder to do UX stuff with C++ and finding great C++ developers has its own challenges. So usually it all comes down to Java. Of course, one can argue that why in the world someone is trying to build desktop client applications in 2017. Usually answer to that question is Internet is not as universal, cheap and fast as some people tend to believe.
I have extensive experience writing professional (i.e. Not consumer oriented) desktop applications in both Python and C++, and you're right on the money.
Java may not be sexy or purty, but it works and you can actually hire people to do it.
