Imagine how extremely frustrating it would be to have a bad base position in comparison to your enemy, or your enemy having an island-like terrain when you build all ground units and could not scout quick enough...
So you will still have a good idea where the guy spawn. But your now forced to scout to see where to take engagements and not.
The players even get to choose which maps they'll play (by eliminating some map if they feel it's unfair) and in which order...