There's a lot more to macros (especially for healers) than just combining multiple abilities. There's <mo> healing, <t>/<tt> for hostile spells, various uses of <f>, party announcements for CDs, swapping hotbars/actions when you summon one faerie or the other or swap Cleric Stance, etc.
It's possible to do silly things that are bad ideas with FFXIV's macro system. It's also possible, especially for healers, to make vast improvements to play style/comfort with them (if not always performance).