There are many that feel the way that you do smr. However, the best answer we have is that we are practicing a Japanese art and we have accepted some of their custom as part of it. They do not consider bowing as a part of a religious ceremony. They see it as a sign of respect. It is done in businesses as well as the dojo. In many ways it is their equivalent of the handshake. And the bow upon entering the dojo is the equivalent of the old practice of removing ones hat when indoors.