Germany has VERY strict laws on what can go in beer - which means its all high quality but rather bland when compared to Belgium which has much more variety.
For some definitions of "high quality". It doesn't contain any random crap, but that doesn't mean it necessarily tastes good. Which of course is quite subjective, but IMHO really the thing that matters, and as others have mentioned a big problem with "non-branded" beer: I don't want to buy "a beer", but either try something new or buy something that I know I'll like. Unless they make it a feature (buy a bottle and get something random, with just a small marking to later figure out what it was) this won't work generally.