[lucozade]

Japan's dominance is likely to be heavily influenced by the fact that families could adopt adults to continue running the business. This would have helped substantially to keep family run businesses running competently much longer than their equivalents in countries where that wasn't the tradition. That's probably not sufficient to explain 50 generation (!?) but could very well explain 20 or so.

Germany, Austria and the UK, mostly seem to be breweries and inns/pubs. I'd speculate that some of this is likely to be monastery or abbey run so, again, it's not as family dependent as most businesses would have been. Also, if you find a popular spot for serving beer in one of those countries, say near a major market, you'd be getting punters for generations.

Switzerland's a bit less obvious. Possibly it's to do with its stability and conservativism?