EA systematically bought out then liquidated the RTS markets' competition when it acquired Bullfrog and Westwood and hindered the creative progress being made for over-the-top games.
C&C got lucky because its games didn't have a tendency to crash like Dungeon Keeper II did, comparatively Dungeon Keeper II to Dungeon Keeper I was an over-saturated mess with no atmosphere and was the first sign of all the other bullshit to come from EA when they acquire an IP.
With C&C they just took longer and longer, spending more money on cutscenes than the actual game itself, we should have seen Rivals coming what with the C&C-4-MOBAEdition