What we have found is that one of the biggest problems in the BI space is the fact people are not able to code and resort to some of the horrific formulae we see. But agreed - including macros would add a huge new layer of complexity!
Parentheses FTW!
Also, the people who write macros are invariably not programmers[1], and the macro code they write is... not so great.
[1] I am a programmer who writes macros, and presumably there are others too.