Maybe because most muslims aren't into following new self-proclaimed "messengers" of God a.k.a. Rashad Khalifa and his cult? Maybe..just maybe? :)
Actually, most muslims aren't even following Prophet Muhammad. If they were, they would follow only the Quran as that is what came out of his mouth and that is what he was commanded to follow alone. The islamic Talmud (hadith & Sunnah) came approx. 200 years after Muhammad died. So, they definitely did not come from the Prophet. The math miracle is one of the great miracles(74:35) which confirms divine origin of the Quran, yet you reject it because of the ramifications of it. That being that 3:81 states that it is a messenger of GOD that will 'confirm' the Quran is from GOD and that is exactly what the math miracle did. So, really it is GOD's proofs and the Quran that you are rejecting.