I don't know, I'm gay, and when I see a picture of Benedict Cumberbatch or Robert Downey Jr, I certainly don't think "Damn, he's accomplished and brilliant"; I think "Damn, he's hot!"
When I see a picture of Benedict Cumberbatch, I think "he looks awfully pinched. He might need more fiber."
I'm straight. Not sure what impact that has.
I don't think that judging attractiveness in itself automatically leads to poor judgement about the person. You find your partner attractive (hopefully) but that doesn't mean that you see ver as incompetent. The problem is when you you can't keep things separated I suppose.