Honestly, I think it's a deflection from calling it the UK variant. Calling it the Chinese virus or the South African virus can be perceived as having racist overtones and could also imply that the disease was caused by being simply being Chinese or South African. This could offend someone of said origin, offend someone on behalf of people of those origins, or not offend someone at all. Your next question is probably, "Why was it okay to call the 1918 pandemic the Spanish Flu?" I imagine that in the present day, it wouldn't be okay. We now live in the age of social media, where the opinions and feelings of a small vociferous population can be misconstrued as those of the majority. A no-win scenario then ensues i.e. a culture war. Those who are offended will undoubtedly express their opinions and attempt to publicly shame those who insist on using the name. Those who believe their free speech is threatened or simply wish to agitate the opposition will spitefully continue to use the disputed name. These arguments distract from the real problem at hand: a pandemic.