are we programed to respond favorably to those subjects that we consider
I don't think so. We often do not find the beautiful attractive. The ugly may attract us, there is something fascinating about a very ugly person or situation. I think you are right in thinking that aesthetic features make life more interesting, but it is too simple to think that beauty attracts and the reverse repels.
There is a wonderful phrase in French describing a certain sort of woman, une jolie laide, both pretty and ugly, which brings out the complexity of these terms. Models with a slight imperfection are often advised to keep it, since it makes their faces more interesting. On the other hand, there is obviously a limit to the number of imperfections we can accept before we are likely to be repelled.
Right now I have blisters all over my left arm from poison ivy, and it looks quite grotesque. They are also of course very painful. On the other hand, they are very interesting to look at, with a strange smooth surface and an uncanny yellow color since they are full of disgusting pus. They are also all over my body on the surface of the skin, and that is uncanny since that area of my body is usually quite smooth. It is difficult to say what is beautiful and what is ugly here, and I think that brings out that there is far more to the beauty/ugly dichotomy than we often suspect.