The only things I've seen that are even 'worth' macroing, is fishing (where all you end up with, it a ton of fish, that probably will never get completely used up) and Hiding (which just makes it so you can be a bit sneakier... and slow as hell). Most of the crafting professions (aside from Basketry) would need to use some form of storage to keep items that they want to craft with. Every time you craft something, storage containers close, thus making it so that if you were macroing, you'd only be able to do it for so long... like 15 minutes, or so, due to weight restrictions. Now, if someone was keeping an eye on the progress of their macro, they wouldn't really be afk... So, afk macroing isn't exactly a fruitful thing, especially due to the soft skill-cap.

P.S.- As far as I can tell, noone would gain any sort of edge in combat, from macroing, since you have to actually hit a creature or person, to level combat skills. Also, if someone did macro say, hiding, to 100, they would reach the soft skill-cap much faster and they would only end up with one really good, but generally pointless, skill.