This is my #2 problem with Ruby, and it's also the reason why a lot of folk love it. I think of macros in the same way I think of RegEx, if you're writing one you better hope it works perfectly because chances are that you'll be the only one to maintain it.
Other Ruby "features" that I dislike:
1. Blocks + Procs + Lambdas are all function-adjacent. Can't we just call them functions?
3. Out of bounds indexes on Arrays/Maps return nil.
4. method_missing() is super cool and super abusive. Again it feels like magic when functions come from nothing.