I'm pretty sure that I know what the answer is (sadly), but I'll try anyways:

Any chance folks in the US can use these, in the US?

This is a genuine question, although I don't have my hopes up. It would be nice to have some actual competition / choices

It costs you nothing but a few hours (heck, you may even make money on the points) to get a Discover card, which you can use on Japanese game sites that don't apply the Visa/Mastercard censorship (they have a partnership with JCB). It's a small move, but most people can't even be bothered to do that much for competition.

Hope you like carrying cash.