+1 -- the overall composition of the customers is given a lot of thought by the chef. For example, if that day there are a lot of regulars that have certain notions about foreigners yes you could end up in a less desirable location. Just as often, there will be regular customers that quite enjoy meeting new people and you can be "upgraded" to primary seats.

I watched this play out at a local place we have been going to for years -- for the first few years we would go (about every other week) we were always sent to the upper room, but after a while we were "promoted" to the lower floor and have had a seat at the chefs counter for many years now -- and even when out of the country for the summers when we would come back we were still given the chef's counter.

It is easy to say that foreigners always get the less desirable seats and in some places that may seem to be true -- but in our experience for the most part the nice places tend to seat their customers based on much deeper / important things than ethnicity...

One other note for foreigners visiting -- there are some / many chefs that do not speak much English / Chinese / Korean / French / German and may be serving certain items that they want to confirm you will have no issues consuming -- in many cases they would rather have you sit with another "younger" / "junior" chef / staff that are better with a foreign language to ensure your safety -- and for them not to worry about it...This is especially true in Sushi places, but it does happen in other restaurants as well...