I think that "pythonic" does mean something, and that when they say "pythonic" they are actually trying to communicate something.

JS and Java... well they're not something I think a lot of programmers want to be. JS has a pretty complicated ecosystem that a lot of developers don't like. Java is good at what it's good at, but it's not very fun.

What I see a lot of is "lisp" or "lisp-like" and "pythonic". Those languages are notable for being considered fun by a lot of programmers.

But yes, it's idiomatic. Python is an idiomatic programming language that has sacrificed a lot for that ideology. Now that guido is gone it's less ideological, and we're getting things like type-hinting.

When people try to apply that same ideology to other fields, sometimes they call it pythonic. When they try to apply the lisp ideology to other fields, they just call it a lisp dialect instead of lisp-ish.