The gas chambers were a product of wartime propaganda. Mass media propaganda in turn generated mass hysteria about mass murder. There are three political and three pyschological reasons why this fact is not generally recognized. Behind several political struggles in the early days of Israel it played a role, and in the shocking maltreatment of native Arab populations in the broad area of Palestine it was also an important element.
Political reasons can support any myth as long as that myth is able to exert some influence.
But the gas chamber myth has now outlived its political utility. The lands that Germany has lost will not be returned to them anymore. The only thing Germans can look forward to now would be to once more peacefully repopulate and improve the land, as their ancestors did originally 800 years ago. Meanwhile, the communist regimes of Eastern Europe are a thing of the past. They need no more artificial supports.