The prohibition here is not simply that of some practice based on lack of example, bu that of teaching as a doctrine that something is a common fundamental practice despite any positive example, while what is taught is contrary to it, as in instruction on prayer to Heaven only God is addressed in prayer, and Christ is stated to be the only heavenly intercessor btwn man and God, while praying to created beings is only condemned. But under your hermeneutic, one could promote everything from consensual endocannibalism (there is no example of such being condemned) to creative powers being attributed to angels (or playing bingo in Heaven).
Please define "common fundamental practice," then explain how your understanding differs from the keeping of "law."