The can would not allow light in like a bottle and apparently the can is simply a better sealed vessel for beer than a bottle. For those of a certain age, bottles were considered superior over cans but it's been changing for awhile now... cans preserve beer better than bottles. Also, it's not unheard of to get "fresh" German beer here. Where I live there are great German taverns with a lot of German beer on draft that is in very good condition. It's not impossible to get great German beer in the US but quite a bit of it *is* aged, mishandled, oxidized, etc., that's true.