This is a practice which has come down to us through generations that what that which is obvious and understood sometimes it is said quietly, taken for granted so that is in fact, it’s not a disrespect to Bismillah in fact it’s a way of respect to Bismillah that is of course it is for granted, this is there but some people do say, recite Bismillah loudly for instance Shafis, they believe in reciting Bismillah loudly and they do and there is no objection, either way it’s okay.
