When I was a wet behind the ears programmer, I learned a cautionary tale about Lisp and macros. Very smart people love macros and are good at them, and will modify things to fit their needs. Problem is, other people think different ways. A flexible language which is easy to mutate results in incompatible dialects.

The sage elders suggested that making the language harder to change (cough Python) is more likely to result in a single widely used dialect, with the differences at the library level rather than in language/macro level.