Electrician is refusing to put TV on rock deco surrounding the fireplace
We are having a new home built and would like our TV to go over our fireplace. The fireplace itself will have a two story rock deco around it, going up to the ceiling. The electrician assigned to us is refusing to put the tv over the rock deco because he says the rocks may fall off or may make the TV mounting unstable. I see so many images on houzz where the TV is mounted over rock fireplaces and look beautiful. He says the only way he will mount it is by telling the builders to leave out the rock deco where the TV would be mounted, leaving a huge empty gap there. Is this a common practice and does this happen often? Can't he just mount the TV over the rock deco? I really don't want to mount the TV on the side wall which is the only other option because it will throw off the center balance of the room. I have attached pictures of what the room looks like. Its not the same exact room because this one does not have the rock deco around the fireplace but it is the exact same layout. Any help/advice is greatly appreciated! Thanks so much!