If I take a photo in public it may contain people that I don't even know. I have no obligation to give those people a copy of the photo nor do I have any obligation to tell them they were in my photo. This happens a LOT in popular public places and tourist attractions.
If I don't know them I'm not going to tag them because I have no idea who they are, but I may want to share the event with people that I do know. Now with auto tagging these people I don't know are tagged in my photos and I have to share not only my photo of them with them, but the entire album? That seems to be really over reaching. Auto tagging and automatic sharing seems like the worst possible option to me.
If I don't know them I'm not going to tag them because I have no idea who they are, but I may want to share the event with people that I do know. Now with auto tagging these people I don't know are tagged in my photos and I have to share not only my photo of them with them, but the entire album? That seems to be really over reaching. Auto tagging and automatic sharing seems like the worst possible option to me.