Welcome to the real world - not everyone is nice and racism exists the world over. Without going too much into the politics of the real world, real world nasty people exist! Some of them play online games! Some of them place CnC:TA and act out their real world nasty views on innocent players.
The problem isn't multiple accounts, or preventing others from taking the centre, it is nasty people using in game strength for nasty real world abuse. It's probably the type of abuse, if it could be proven, would be illegal in many countries. But it can't be proven to the extent that EA will act upon complaints.
This type of problem probably isn't confined to EA games, or CnC:TA. Reading the online press you see the same thing all over.
There has been many discussions on the King of the hill nature of this game, and of multiple accounts played by the same player. Neither of these is going to change soon.