speculation (in chinese) about the reasons why
the june 4th ad could pass through the newspaper editor/censor is that the editor/censor is too young to have any idea of the incident which happened 18 years ago.
there are people who want to deny it, there are people who want to remember it and there are people who don't know/care about it.
i can verify the gen-III with my experience of 《the unkonwn story of Mao》, while there are old guys who are angry about the book when you present it to them and there are some who desperately try to find a copy and read, young people are totally indifferent to the book.