Afaik, most US citizens staying at Japanese AirBnB's (for example) do not speak Japanese nor know the local culture. Do you think that's a problem as well? When I stayed at an AirBnB in Italy I knew nothing about the local culture nor spoke the language, nobody thought that was an issue.
Or is this just, you know, racism?
Incidentally, insulting people is not conducive to healthy debate. Please consider whether calling your opponent (or their actions) racist will increase our ability to persuade them to change their position, or just make them entrench their position (even against more persuasive arguments).
How are war refugees different from tourists on vacation. Amazing. You just personally contributed to wearing out the word "racist" and growing the new right wing.
Most AirBnB guests are financially secure, have a vested interest in not damaging your property, and aren't likely to be scared/stressed/traumatized.