[brudgers]

One reason might be a development environment preference since developing directly in Jython would typically imply the overhead of the JVM. Another possible use case may be porting where a transpiler could address differences between implementations automatically that would otherwise have to be addressed more manually at the source code level.

To put it another way, Jython makes obvious sense when the primary target is the JVM and there's little legacy code. As target platforms proliferate and the code base becomes cruftier, it may become a less obvious choice.

I'm not sure the Pythonic "only one way" extends quite so far as to make Jython worthy of monopoly status.