WoW is not an RTS. The strategy and skill in wow is managing your resources (cooldowns, mana, energy) and timings. Macros do not remove that in any way.
Plus, macros are not “allowed” by Blizzard, they’re a literal feature of the game. They’re not an addon or a mod, they’re literally a part of the game’s UI.
They’re there to be used, just like hotkeys or action bars, which technically “automate” the proccess of opening the skillbook and clicking the skill, by your logic.