Mainly the Thalmor try to ban it, because if there's more things that are not Elven culture (such as the retarded Thalmor believing they created the moons) then more people will rise up and realise the Thalmor CAN be fought. Essentially, the Thalmor are actually in a bad position. Hammerfell was retaken, Skyrim is a very strong province and if led by the Dovahkiin, impossible to defeat (after all he/she can just contact Odahviing to destroy their army. Lol.) but mainly, the Empire would most likely see the threat of the Thalmor as nothing. "Elven Supremacy" is often mentioned by the Thalmor, yet I saw no Elves help the Red Mountain crisis, no elves helped in Oblivion... all they seem to do is invade and annex. Yes, they are the nazis of The Elder Scrolls.