Wow really? I've never - that I recall - seen a vending machine selling beers, I suppose because kids could buy them if they were in a place that was open to the public. In your building I suppose I suppose it's not open to the general public, but kids who live in the building could save their pennies and get fucked up if they wanted right?
To be honest, it would be so easy to make a machine that required you to put your driving licence or something to prove your age and which had a maximum of, I dunno, two or three cans per purchase with a re-set every five hours or something, so no-one could get wankered. So I don't see why they can't have them in some countries... maybe not in the UK, but good countries.