It doesn't even have to be a Muslim country. In Brazil they had laws that prohibited the sale of alcohol inside the stadium, but when FIFA brought the world cup there, they simply changed the law, and sold alcohol in the stadiums.
At the end of the day, money talks.
The problem with Qatar was that initially they announced that alcohol will be permitted inside the stadium for a limited duration. But then two days before the kickoff, they changed the rule and told that alcohol will be strictly prohibited except for those who hold the most expensive tier tickets. The fans who booked their tickets many weeks ago felt cheated and by then it was too late to cancel their travel plans. Budweiser was one of the sponsors for this event, and they also felt deceived as a result of this new restriction.