[abuchanan]

Been meaning to write a blog post about this, but my 2 cents is this: The degree of change in a programming language ecosystem is inversely proportional to the expected lifespan of the systems being built using that language.

One caveat for the pedantic - yes, as the expected lifespan becomes zero, so does the rate of change. (i.e. you have a dead language)

The lifespan of a system gets longer the closer you move from the UI through the business logic and finally to the underlying data. It isn't uncommon for a business to rebuild its frontend website every 1.5 years or so, whereas their systems-of-record might be expected to last a decade or more.

Since JavaScript is used most frequently on the frontend (for obvious reasons), and new frontend projects kick off more frequently, there is less need for backwards compatibility, fewer risks to trying the new and shiny framework, etc.

I'll probably get internet slapped for saying this, but I would predict that JavaScript never does become the preferred language for the system-of-record type backends no matter how quickly it evolves. In fact, precisely BECAUSE it evolves so quickly. What makes it a great fit in the one niche, makes it a poor fit in the other. Lest this be taken as JavaScript bashing, note that the same thing happened to Java in reverse. It was evolving too slowly for the frontend niches it tried to move into years ago.