Toto sells porcelain products in the USA, it just hasn't focused on marketing the Washlet until fairly recently. Whether that's due to negligence on their part, or American revulsion to the idea of toilets squirting you with water[0] is unknown.

[0] Japanese toilets were long the butt of stand-up comics' jokes. I remember one such comic ending with the punchline "I'm being raped by a toilet!"