Well, to be fair, the difference is that with Python (or basically any other langauge) a change in a library may introduce a bug, but you won't have to throw away the library or even substantially change your code, save perhaps for some temporary work-around- and the bug will most probably be fixed eventually.

With javascript, as far as a I can tell, "change in a library" means you do indeed throw out the library and adopt a new one, then write your entire code again from scratch and repeat the cycle next year. To me, that sounds like madness and just makes me happy I don't have to deal with all this.