I think it depends on the man, also. Beards are a weird thing. They mask a lot of your facial features, they mask your emotional expression.
I guess if you're plain ugly, they conceal a lot of things, and, assuming you have good beard growth (according to the dimensions BV mentioned), they give you an air of mystery which can be appealing.
I personally don't understand why attractive men with expressive faces wear beards... because I think it does nothing much good for them in most cases.