Why Are The Nazis Such A Badly Regarded Organisation?

The Nazi Party governed Germany from 1933 to 1945 and, with their territorial aggression, provoked World War Two, the most devastating war of all-time.  That fact alone would make them highly unpopular, particularly among the millions of families left destitute and bereaved as a direct consequence of that conflict.  However it is the evil inherent in the Nazi ideology, and the brutal manifestation of it in the millions the Nazis systematically murdered in The Holocaust of World War Two, which is most responsible for the low regard in which the Nazis are held by most people.  

This ideology's central tenets of racism, anti-Semitism and the arrogant belief in the superiority of the Aryan race has, along with an authoritarian disregard for individual freedom, not to mention lives, made Nazism an ideology abhorrent to anyone who believes in democracy, individual liberty and basic human decency and morality.  Unfortunately, not everyone regards the Nazis badly - Neo-Nazi groups attempting to revive the party and its ideology still operate, both in Germany (though Nazism is outlawed as a political ideology there) and abroad.