I was really drawn to the title of your post because that's just what I have done--well, over the last few months--and I went with Clojure. I want to absolutely focus now and I can see the momentum is gonna take me for at least the next 10 years. I never rode the Rails train and after becoming a functional programming believer I'm kinda glad I didn't in retrospect, but I had always been envious of people who did make that decision to become
good at a stack. I agree with you that the error exploding in Clojure is not nice, but to me it makes up for it in being on top of both Java and JavaScript (having been a JS dev previously, but being entirely tired of the convulsion of frameworks and build tools and module systems.)
It's a lisp that, as opposed to Lisp and Scheme, is not fragmented and seems to have mostly a healthy, united community. I see amazingly smart people, and so many of them, pushing Clojure forward (Rich Hickey, Stuart Sierra, David Nolen, Chas Emerick to name a few) and yet it's more approachable than Haskell. And I think these people will eventually find good, standardized solutions for things like the awfully ugly stacktraces.
Clojure doesn't really have a 'framework', and I like it that it's really composable in that sense. But things like Ring and Compojure are lightweight no-brainers, much like Rails is a heavyweight no-brainer for Ruby. What I want to say is, unlike JavaScript, after having picked Clojure as the language, the choice of everything else is mostly always a no-brainer (e.g. leiningen, core.async, enlive/hiccup, maybe Om soon.) And that really pleases my choice-avert brain.