Its not so much the area I suspect, rather than the razor blade is so sharp and gives such a clean cut that it bleeds very easily.

The face and head have a lot of blood vessels near the surface of the skin as well, to feed all the small muscles under the skin and as a result of your skull being full of brain (not in my case, but you get the idea! ) eyes and other stuff! So cuts to the head do tend to bleed pretty profusely.