Besides that it's trendy on hackernews to make fun of designers they are an important part of every commercial product. As an designer it is really hard to contribute to oss the whole environment is just so hostile for non devs.
It's not censorship you can buy the book if you want too just not from amazon. It's like your german jewish bookstore didn't want to feature "Mein Kampf", until the Reichskristallnacht they had every right to do so and so does now amazon.