1. According to Judaism the Oral Law was give by G-d to be repeated from generation to generation orally, so to write it down is sin!
2. The assembly of Israelites was given the Written Law. They were commanded to keep it. There isn’t a Biblical record of the giving of the Oral Law. Why not only orally repeat the Written Law from generation to generation and not write it down?
3. The Mishnah, Talmud, etc. as the written Oral Law never state “G-d commanded”, “G-d said”, etc. The writings found in the Oral Law state “Rabbi ____ said”. G-d is never found to be quoted with His identity as in the Written Law.