The why of macros

Good analysis by Vladimir Sedach:

The entire point of programming is automation. The question that immediately comes to mind after you learn this fact is - why not program a computer to program itself? Macros are a simple mechanism for generating code, in other words, automating programming. [...]

This is also the reason why functional programming languages ignore macros. The people behind them are not interested in programming automation. [Milner] created ML to help automate proofs. The Haskell gang is primarily interested in advancing applied type theory. [...]

Adding macros to ML will have no impact on its usefulness for building theorem provers. You can't make APL or Matlab better languages for working with arrays by adding macros. But as soon as you need to express new domain concepts in a language that does not natively support them, macros become essential to maintaining good, concise code. This IMO is the largest missing piece in most projects based around domain-driven design.