At the end of the day why deny history, it is almost 70 years in our past, but it happened. America doesn't ban CSA regalia, Australia doesn't ban the flag of the Southern Cross, all symbols of rebellion. The star and sickle, countless atrocities performed under that banner, the same can said about many other symbols of countries like India, Britain, China, Japan, Ireland etc etc etc. If these particular symbols are drawn and deface people property that's is the illegal act not the symbol. In the western so called democratic world it time governments get into the 21 st century and not linger on the past.
Some governments move into the 21s5 century. I the words of Forrest Gump, "that all I have to say about."
Some things just should not be forgotten. Industrialized mass murder is unprecedented in history, the swastika is not just a symbol of some sort of rebellion but the icon of an inhuman and racist ideology... An ideology still too alive in modern western societies!
Germany is doing a good job keeping memories alive and opposing neo-nazi movements. Many other western nations still largely ignore their dark spots in history.
The biggest threat for mankind is ignorance.