It's the same in Western Europe, the difference is that cheap lease deals and finance have made them affordable for a significant amount of people and so these cars are extremely common. You see more 3 series than Toyota's or Hyundai's.
Every sales graph I've ever seen has relatively cheap cars such as the Fiesta, Golf, Corsa, etc. at the top. Not big Mercedes or BMWs.
But people who want saloons and estate cars are largely buying from the three Germans, and not Japanese or Korean.
So in the USA, or at least in California they are very common. Part of their popularity is their fleet use makes them direct cheap in the used market, and they tend to be pretty reliable despite the complexity of two separate drive trains.