Clojure already says YES where other lisp-based languages said NO to. (Instead of wrapping all java, let's use it for its strength. Don't just use list, use vector, map, etc. No tail-recursive? Aight, let's do it anyway and find a work-around)
Now, we make to differentiate users and what they ask. Is it a new clojure user who is used to C++ and try to code C++ in clojure and suggest missing features? Or an experienced clojure user offering useful patches to the community. In the first case, the right answer should probably be "Oh, but XYZ is already in Clojure, it's a little bit different than what you've been used in C++, but in fact, it's even more powerful. Here's how you can do it [...]". In the second case, it's more complicated.. but we should go toward the Yes if it adds real value to a day to day task. I mean, even thought clojure is great, you can't guess everything that will be needed.. so you shouldn't be shy to add missing stuff.
Now, we make to differentiate users and what they ask. Is it a new clojure user who is used to C++ and try to code C++ in clojure and suggest missing features? Or an experienced clojure user offering useful patches to the community. In the first case, the right answer should probably be "Oh, but XYZ is already in Clojure, it's a little bit different than what you've been used in C++, but in fact, it's even more powerful. Here's how you can do it [...]". In the second case, it's more complicated.. but we should go toward the Yes if it adds real value to a day to day task. I mean, even thought clojure is great, you can't guess everything that will be needed.. so you shouldn't be shy to add missing stuff.
Still, Rich's answer is pretty great IMO.