Turing-completeness doesn't guaranty any sort of I/O, which I would make a requirement of a nice language. I may be able to write a Lisp interpreter using Conw

Turing-completeness doesn't guaranty any sort of I/O, which I would make a requirement of a nice language. I may be able to write a Lisp interpreter using Conway's Game of Life, but then I have to represent my Lisp code within the cellular automaton. (The same thing applies to, for example, Brainfuck.) Also, I'd say that any language which requires me to write a Lisp interpreter to be nice is not a "nice language".