Players will tell you that they don't like it, but on-the-fly random number generation (rng) is seen in almost every match in the three biggest MOBAs (League, Dota2, and HoN). Why is this?
Firstly, I want to establish that randomness in games isn't a problem on its own. Card games like poker hinge on it, while still being enjoyable and competitive. The problem is that in a card game, players are betting on their ability to read their opponent. In an RTS, players are betting on the rng.