Why the developers refused to start new projects using super easy JavaFX package? Why they continue their projects with traditional Java Swing package? What will be the future of JavaFX? Will it be discontinued? I heard Java Swing is discontinued and no more future enhancements will be made. As a Beginner what should I learn.
Java AWT hasn't been discontinued, so it's unlikely that Java Swing will be discontinued.
If companies have existing Java Swing projects, it's usually not worthwhile financially to convert them to JavaFX. There's also the problem that there are not many good Java Swing experts, and if you're lucky enough as a company to have a Java Swing expert that's also a User Experience (UX) expert, you don't want to rock the boat.
Companies (and Java teachers) that rely on JApplets and Applets to deliver their UX have bigger problems with browser support than companies using Java Swing. There are companies still using Java 6 because of legacy requirements or client requirements. For those companies, JavaFX isn't an option.
There are still more Java Swing experts on Stack Overflow than JavaFX experts available to answer questions.