I noticed users in the United States can't sign up. ("United States" is not in the list of countries in the required Country field, and it's also excluded from

I noticed users in the United States can't sign up. ("United States" is not in the list of countries in the required Country field, and it's also excluded from "18. Regional Service" is the Terms of Service.) Is that intentional? It could be part of the reason for the slow uptake.