1. You can not really juge the source code of a language if you don't the language. Reading alot of functional code is almost always easier then OO code because of pure functions. Look at this video for example at the videos witch can be found here http://www.janestcapital.com/technology/ocaml.php

2. The learning curve of those languages is not bigger then the learning curve of other languages. Time time I spend with making pretty OO designs in school was way bigger then the time it took me to learn clojure and FP in general but this of course is a issue we can not solve. I just don't like it if people say something as if it is a fact.

3. Is it more convenient to do this array.select &:even? better then (filter even? array)

The later seams more intuitive to me and I didn't have to learn more syntax.

4. In Lisp not every DSL looks like Lisp.