I suspect I'll eventually outgrow my quaint process of copy/pasting here and there and embrace some variant of vim-slime. I agree most programmers spend more time thinking than writing code, but the two aren't so separate; what I like tremendously about repls in general is the ability to think with the aid of the computer, it speeds things along a lot. When the computer and I produce something worth keeping I save it. Of course I like my couch sessions (in lieu of a hammock) when they're needed.
It's easy to make it seem like a problem is bigger than it is. For all the ranting I can do about repls for various systems, it's not that big a deal in the grander scheme of things. (With repls specifically it's just an annoyance that readline behavior isn't default like it should be, not necessarily unfamiliarity with the ecosystem at large.) If the biggest criticism of Clojure is its crappy default repl, then one should think it must be a killer language if no other criticisms were mounted instead. (Personally I've only done a few applications with it but I'm already convinced it's fantastic even if I can think of some issues more important than the repl.)