To be fair, there's no other industrialized nation with the diversity or cultural polarization which exists in the U.S.
Actually, the USA is only about in the middle in terms of diversity. It's ahead of most other developed countries, although there are a few notable exceptions.
The USA is not extremely culturally polarized compared to many other countries. Granted, it's more diverse than your average European country (not counting the examples above and a few others), but there are much more diverse countries out there with more functional political systems.