You seem to imply that beauty is an intrinsic property like good health, and that it is not subjective. It seems clear to me that beauty has subjective components too, and that our concept of beauty is also affected by evolution. As a evolutionary biologist, one could ask, do people evolve to meet our perception of beauty by mate selection, or do our brains evolve to see fertile and healthy people of the opposite sex as beautiful? I would think a little bit of both, though the latter seems more convincing. Clearly male apes find female monkeys beautiful in a sexual sense, but I personally don't. So it must be my brain wiring, not an intrinsic concept of beauty.

Given these thoughts, it doesn't seem surprising that there is some correlation between positive personality traits and beauty AS WE SEE IT.

I would also guess that people with positive traits spend more effort to be healthy, practice good grooming, and have a generally more beautiful appearance as a result of effort, not just genes.

So, not surprising in my opinion.