I agree. But you can't deny it is still a lot of people who use Xi as their last name. There are nearly a million in China alone. But I agree that is a weak argument. If a surname is a problem, someone can use that logic to claim the name Corona virus was damaging to the Corona beer brand or the delta variant was damaging to Delta Airlines.
I meant it as a joke but it is a potentially slippery slope. However, I personally believe there is a simpler explanation: they wish to disassociate the virus from the country China and as a consequence, the racism Chinese immigrants have faced all over the world. This should not be okay irrespective of whether one believes the lab leak theory or not.