I'm not so sure there is anything xenophobic about not being stupid.
Agreed.
From both a provider's and a customer's standpoint, and as evidenced by Stay'tee's rental, something less automatically exclusive might be in order. If it were my website, I would have had an automated response that would have read something like this, "Visiting the US and need a truck or van? We'll walk you through the process! Contact us at (fill in the blank), and our staff will help you."
I've worked for U-Haul, rented apartments for years, and currently rent AV equipment - it's important to have a good idea why your customer is renting, what they are renting it for,
and that they know how to properly use it if for no other reason than to know that their needs are being attended. The more questions and personal contact a hire company has with a customer, the easier it is to suss out the nefarious, and the better taken care of the customer will feel.
What I've learned over the years? It's the walk-up, last-minute rentals that bite you in the A$$ and get you into trouble, not the ones that are planned two weeks or two months in advance through good communications.
On the other hand, to automatically shunt foreign business on a website through exclusion because of country of origin may not be xenophobic, but to do so without engaging the customer is bad business.
I'm glad Stay'tee found his work-around.