I would agree that you'd like to think a head manufacturer would use something other than a gasket to determine a port layout for a new head.
That being said, I've seen many many parts brought to market with things done down right wrong, or existing designs "improved" upon that were just a big step backwards(newer style BB Victor head for example). I've shaken my head in wonder more times than I can remember about what someone was thinking when they designed/produced new performance parts.