Well, I'm not sure that I agree, at least not totally.<quoted text>
Sexual attraction is driven by genetics, it's connected to the reproduction system a species utilizes to assist in genetic diversity. Are you saying that the birds which choose based on plumage are just choosing based entirely on cosmetic traits as well? Same thing.
I can't say why birds choose their mates, but plumage isn't a survival strategy in itself. A male with bright plumage may be demonstrating past successful survival ability by being conspicuous. As long as that conspicuous plumage isn't compulsory for the immature males, it's showing off. I guess female birds tend to go for the punks too!
That mating pattern DOES suggest that child rearing is mostly a female responsibility for such species. Is there a moral to this story?