I actually saw a 'trope' named after B'Elanna and I can't find it now. It had to do with believing an actor to be more attractive as an alien than he or she was in real life. It was something I found by accident, didn't bookmark it.
That's a shame, it would be an interesting read. Sometimes I wonder if in many ways it's an outgrowth of the orientalist stuff of the Victoria era, all caused by the biological reproductive urge to seek out different genes to improve our children's chances of survival.
Sometimes, to paraphrase Freud, sometimes a sexy alien is just a sexy alien.