I tend to think you're mistaken when you hear and see how these are worshiped and bowed to by members, as well as the Popes continuously leading the church to emphasize these as they practice these rites/rituals and 'use' these symbols in their worship. God clearly warns against creating any idol before which anyone should bow.... It goes without saying that the countless 'images' of Mary strewn throughout Catholic churches all over the world are most assuredly shrines of idolatry since thousands of times a day Catholics over the world break the commandment of God by bowing before these images in worship.
Art of all religions have to do with culture of the participants and passed down tradition. Introduction of new religion into existing cultural tradition will naturally result in blending of old and new.