Exactly. If one were to look at my top-level reply here and ask "why?" for any item I listed, in basically every case the answer would be "It works, and I know it." I could get more done faster using that stack than a stack I'd have to learn from scratch.

That said, there's a time and place for experimenting and learning new stuff. And I am interested in trying Elixir at some point. But to "get stuff done" in the near term? Yeah, it's going to be mostly Java/Groovy, Grails, and some Javascript. Hell, I might even break out jQuery just out of sheer familiarity, if I got stuck doing something using vanilla JS.