Here in India, you'll see Swastikas everywhere. Till I grew up and read about Nazis, I never even knew that there was anything negative about the symbol. It's just a symmetric symbol and I don't see any reason for blocking that symbol.
The author might not agree with the political views of the Nazis but that is frankly not a reason to ban a symbol. To use the author's words, no one in the educated world would consider the Swastika as a purely Nazi symbol. Then, why block it for people who have other sentiments attached?
PS: Personally, I don't have any affinity to the swastika or any other symbol. My point is that its just a symmetric shape. Some people have positive feelings, some have negative, others have none at all. As a service provider, your duty is to cater to consumers without letting your personal preference mix.