I think we see so much churn in JavaScript because we've forced the weight of the entire client side web onto the back of a single language. JavaScript must satiate the technical needs of all organizations across every consumer facing device and operating system. Like all languages, JavaScript has its weaknesses, so its not surprising that we find JavaScript to be a less than optimal solution for certain types of problems, but since JavaScript is generally the only option available for scripting logic in the browser, it's pretty natural that we see an explosion of libraries and frameworks to compensate for the fact that the JavaScript hammer is the only tool that exists in the client web universe.