Lisp is powerful, but that means it is a double edged sword, like C++.
http://www.drdobbs.com/architecture-and-design/macros-considered-harmful-international/228700263People think lisp macros are different than precompile preprocessor macros, but in fact they are more similar than you think.. possibly even worse...
I'm not 100 percent against lisp, as it is powerful - but one still has to be a skeptic of it. An A.I. may need a powerful language without too many limits (an A.I. would not like Java) but humans need some limits and we aren't smart A.I. who totally understands lisp. So humans need languages like oberon, plain C, Go language, etc. But would an A.I. brain be limited with plain C, Go, etc? probably. But I could be wrong - maybe it would figure a way to make use of simple languages and just write more lines of code. Trade off: powerful languages can say more with less lines of code. Double edged sword (Perl, Ruby, complex mind games)