Why do people act as if all Muslims have the same beliefs rules and customs? They don't. Each group has it's own rules and customs, some are more lenient, others are strict and conservative. Again, don't lump them in all one group and say "They are all the same." They aren't.
Good God.
The Qur'an prohibits alcohol. Any Muslim who buys, sells or drinks it is not a true Muslim because he is rejecting the Qur'an. End of story.