I don't think anyone meant that Miyajima is "not worth it." It definitely is worth it if you have the time. My thought was that you might be tight on time. It seems that you move pretty quickly so may have the time anyway. If so, I definitely think you should go to Miyajima. Again, if you have time, the ropeway up to the top of the hill above the temple will give you a nice, sweeping view over the island and part of the Inland Sea for a memorable photo.