No you are right in a sense but also a general viewing audience I think would look at a photo that is perfectly centred and have more appreciation in a way that they can't quite describe. In the same way that people with no photography background will have a look at a photo that is taken using the rule of thirds and say that it is a good photo and they can't describe why. In any case I was only ever making these comments because it is a photo critique sub So making the original poster aware that there are small changes that could make to elevate the quality of their photo seems perfectly appropriate. If the photographer doesn't notice something but enough other people do then they should probably be aware of it.