Among the holidays I quoted, there are only a few ones that are exclusive to America. Spring break is an excellent theme for porn.
But overall, I totally agree with you. It's not only about traditions ... but also the way people view certain things.
For example, most scenarios are made in a way that the characters interract like American people. It is easier for American people to impersonate those characters but we could bring new perspectives to enjoy things differently.
For example, I wrote in the suggestions thread about different fictive scenarios where we belong in a fictive culture. For instance, we could impersonate people from tribes living in a fictive country with different rules and different abilities, power and visions ...
