I'm a Hetzner user in the US, but I pay for it with PayPal and was never asked to give my passport or identity. Americans are very rarely asked for these documents online, and even then it's typically only for government or financial services. It's also drilled into us that this info can be used for identity theft, so it's only natural to be wary of any non-government entity asking for them.

FWIW, if Hetzner had asked for my passport when I signed up, I would not have given it either.