This is not an issue that requires having to update any servers, though. It's simply about the webpage design, modifying pulldown menus to add one more choice ("foreign"), getting rid of phone # as a required field, etc. Entering foreign credit card and having the transaction go through (at least, in my case which is US-issued) are typically not an issue.

OTA may facilitate hotel bookings. But there're so many other situations (including things that don't involve payment)... reserving bus seats, ordering things, even just sending inquiries sometimes... where this limitation becomes an obstacle.