While Seattle's Russian community is huge, there are other factors/reasons that Aeroflot flies to Seattle. Chicago and Miami have significantly larger Russian communities, and Aeroflot has suspended service to both in recent years.
Thank you. I can't let my pet peeve go unnoticed. People, please get this through your head. Just because a city has a large nationality population, that alone isn't going to justify nonstop flights to the home country. As I've said time and time again, if that were true, SAT
would have nonstops to FRA
would have nonstops to DEL, and so on. Business travel drives these flights. Many shipping and technology companies in Seattle have work in Moscow, and Seattle is also relatively close to Moscow via the Great Circle. That's why SEA
has these flights, not because of its large Russian population.