This is madness! Personally, I don't have any problem with Bud, I'll drink it if nothing else is available, but surely there must be allowance for competition. I have an Economics AS, and I remember that monopolies are bad. BAD! And it's screwing over the small time businesses who would be looking at the World Cup as a means of making serious cash.
I'm no jurist or anything related, but there's an exclusive contract betweeen A/B and the FIFA. The thing might be that the stadiums are private property where the "landlord" gives the right to sell beer to whoever pleases him.
But you are certainly right, monopolies are bad. And the small businesses must restrict themselves to sell at least one mile away from the stadium IIRC. I'm quite sure this will lead to everyone bringing his own beer into the stadium. With the problem that cans and bottles probably won't be allowed inside.
I'll be more enthusiastic about encouraging thinking outside the box when there's evidence of any thinking going on inside it.
(Terry Pratchett)