Hello Venus,
Sorry you had a bad experience with these two. I would say people of all nationalities are capable of being awful, but for the most part, our guests are wonderful and teach us new things all the time.
Reviews are hard. No matter how great you do, some people will unfairly mark you down. it happens in all customer-facing situations: retail, restaurants, services. Learn what you can from reviews with substance, and use their ideas improve over time for future. For the unfair or unexplained downgrades, try to ignore them. IT IS HARD! Remember, it's not you, it's them.
Best wishes with your next few guests,
Yours, Marc (and Linda) in San Jose California)