I think that's a good point. Another US bias may be that it seems fairly common to date or marry co-workers, which is not the case everywhere.

In some (maybe most) countries in Europe, most people do not move far away from their initial place of birth. Could be for cultural reasons or just because distances are smaller. As such, by the time they are of a dating age, they already have a rich and extended social life. They don't necessarily require the work place as an important source of meeting a partner. In a way, this affords the luxury of keeping work and social separate.