The need for a government-limiting constitution? Sure, some people like Hitler or Stalin disagreed. A GLC would hinder their goals immensly. But we're all here on FR, trying to convince each other to agree with our derivations of morality - IOW, trying to convince each other that society would be better off if the majority believed like we do. Pointing to individuals who had different conceptions of morality is irrelevant to that.
OTOH, Hitler* & Stalin were products of specific moral codes. They both believed that individuals, morally speaking, are mere cells inside a larger organism. (The economic class for Stalin, the race for Hitler.) According to them, these super-organisms have fought their rivals throughout history in a deterministic dialectical process first described by Hegel a century earlier. They both ended up murdering millions of innocents & grinding the rest of their subjects into the dirt. And why not, if no individual is a moral actor - only the collective to which they belong?
Your system of morality seems to work. As long as you can dictate the base standard. What if Hitler was right? How can you know for sure?
Moral collectivism makes no sense, and we have a century of contemporary history that confirms this. One could make the argument that evil must exist in order for us to recognize the good, and even America had a mini-love affair with socialism for decades until its terrible effects elsewhere became too obvious to ignore.
*I must point out it was CyberCowboy777 who first mentioned Hitler!
One last thing before I go. Jenny, why do you continue to appeal to history? Is it that your "philosophy" is lacking? Why do you need history to prove your points, when "logic" and "reason" should do the trick?