Unfortunately, as the owner of the IP, they get to set their own reasons as to what they support and why, even if that is completely illogical. I would agree that the resourcefulness of some users might have over-extended EA/DICE on their ability to understand, evaluate and prevent 'cheating' simply because they weren't prepared to handle users with the knowledge to run the game on something outside of Windows.
However - if these 'unsupported' OS configurations are going to be open to bans, this needs to be written into the user acceptance agreement so there is no confusion. (Which they might be, I do not know)