Changes to something like StarCraft II's online game need to be very carefully considered because of the fragile balance between the Zerg, Protoss and Terran armies. Even the slightest change to damage totals, build times and resource costs could give one side a huge advantage. It's like if the NBA added springs into one teams' shoes or bumped a particular court's rims up an inch any potential change has big implications for gameplay and competitive advantage...