Isn't that part of where the "high APM" thing comes from - players having to micromanage their army movement?

I dunno if that's an explicit discouragement though.

Pathing in the 90s was all sorts of bad for all games except Civilization (because there's no collision detection in Civ, so... all units just walk on top of each other).

Starcraft also had a really low unit-cap. I think it was 200 points, so aside from the zergling rush (zerglings counted for 1/2 a point, iirc), you just couldn't really human-wave anyway.