[edburdo]

Why do you need to keep current on multiple languages? Is it to keep you still marketable so you can leave? Or just a bragging right for yourself?

Why not specialize in one or two languages... become a leader and specialist and not a generalist.

[dozzie]

I'll tell you why to keep being a polyglot: to have a choice of tools for solving problems and to have a perspective.

I routinely write tools in half a dozen languages and pretty much always I'm glad that I could choose one or another, because it fits the problem at hand much better than anything else.

And the perspective is about knowing different approaches to a problem. Sometimes I transfer the good ideas from one language/runtime/framework to another, where it makes sense, but is not a common practice. And I can easily use a language I haven't had much experience before, just because it's the same paradigm as I already know from several other languages (I did this a few times already).

And no, I'm not a generalist. I'm quite specialized in my work. I write tools for OS administration.