I think the term 'neutraceutical' is the key, frankly. It seems to me that it would be just as easy to tell people to eat red meat as a part of a balanced diet... however pharmaceutical companies wouldn't capitalize on that.
I suppose as well that this could fool a number of vegetarians into believing they were getting this supplement without it being an animal product (how many animal products come in the form of a pill?)
I'm with you on the matter of deer and moose. I'm not sure about the US, but in Canada, elk meat comes mainly from domestic livestock now, so isn't really so much different than beef.