If EA, and understand that they would have to team up with both Microsoft (Cboc) and Sony (PS4) to do this, wanted to allow mods, they would have to put up many restrictions as to not break the consoles and make damage to them. You can't really change the files in the same way by yourself as on a computer, the system is completely different.
I think the reason for this is that it's more or less technically impossible unless EA handles all the mods and cc allowed for the game.
