I did extensive work with Java (and a small amount of JavaFX) as a professional developer in a corporate environment. Java was tolerated there since it’s a captive audience. But in general, Java GUI apps are not well loved. Most people prefer native UIs, and JavaFX doesn’t come close to that.
I don’t know Gluon at all, but looks like development options can get costly. Especially in the open source world, developers typically avoid costly platforms.
