The other issue is that macro authors tend to create embedded DSLs. That makes the code hard to understand, unmaintainable and write-only-once in the long run.

Strangely, I find the Scheme and Lisp community to be pretty good at creating reasonable macros. (With exceptions, I'm not a fan of the LOOP macro.) Maybe that's because they use them less for syntactic sugar and more for really expanding the language. Still, there are too many DSLs and you can be lucky if you understand your own CL code ten years later.