Okay, I really don't spend a lot of time following what the Hollywood types do, but I saw something recently somewhere about how Matthew McConehay doesn't use deodorant and sometimes is pretty ripe smelling. Of course most of us never have to be close to the man; so, it's not an issue for us.
As Dukey says, pheromones mixed in could have something to do with how we respond, but I also think whatever feelings we may already have about someone colors how we feel. If a friend has bad body odor or breath, we may overlook it, or even suggest they do something about it. If someone we are not fond of is afflicted, it just contributes to the bad feelings we have about them. If it is someone we don't know already, we may have a hard time generating much interest in getting to know them better.
Another thought is that when one is regularly told he or she is beautiful or otherwise wonderful, there is a tendency to want to hear more of the same. So, a good looking person might just be more aware of things that have to do with being appealing.
Then there's the whole balance and health thing. People with more balanced appearances are considered more attractive, and their physical appearance of balance ties in with their overall balance which includes better health. Better health no doubt includes more attractive smelling (or less disgusting smelling) sweat.
I'm not striving for political incorrectness here. It's just that there really might be a connection.
[Not to copy Mr. McConehay because I was doing it before I'd ever heard of him, but I don't do deodorant either. Swimming as much as I do helps keep the need down, but I also use rubbing alcohol once in a while to kill whatever bacterial activity my be trying to get started.]