Well, my dracon characters (draconic humanoids) are fairly attractive for their species, but this is due to their role as an artificial race in-universe. They were made with the features that most nearly conform to the biological basis for beauty: strong males and fertile females. Like it or not, those two visible qualities are what most directly drive our sense of beauty, especially for females. This is why things like the body parts which indicate the ability to bear and feed children are so attractive for humans, as well as visible indications that a woman is not currently pregnant. Call it old-fashioned, but that's how and why it works. Natural selection and all that. Even if a species was artificially created, it would have been made at some point by a species which emerged naturally and evolved expectations of beauty driven by its biology.