Not only unit movement (micro), but your ability to macro (manage your economy, produce new units, expand your base) will be great affected if you have low APM.

Not only unit movement (micro), but your ability to macro (manage your economy, produce new units, expand your base) will be great affected if you have low APM. In that sense, APM is very important. I'm confident I can beat any bronze league (lowest tier) player with nearly any unit composition (even when they pick a build that is a direct counter to me) simply because I will way out produce the bronze player since I'll be able to stay on top of my macro due to superior APM.