Becasue

So a Hoodia is walking down the street looking for some fun.

It walks into a bar and says, "Gimmie a beer."

The Barkeep replies unto it, "We don't serve your kind here."

Offended the Hoodia looks back unto the barkeep and aske, "How could you do that? Why would you do that.

The bartender opens his mouth and speaks saying, "Because."

To which the creature gazes back and asks . . .

Here is the trouble, I need a punchline. Can you help?