That was poetic justice. Also, they did not want the Nazi criminals to have any burial site, tombstone or anything. Remember their crimes but erase them as persons.
I just remembered reading a story one time about when the British captured Himmler. He subsequently committed suicide shortly after. The officer in charge ordered a senior enlisted to dispose of the body in a remote place. He was to take no one with him and was never to reveal where Himmler was buried.