The cream rises to the top and so does the scum. This is true not only of broth but also of human affairs. Sometimes good people attain success, but there are numerous instances of scum rising to the top. Therefore, the character of a human being cannot be solely judged based on the success or failure that he has attained. An extremely successful man might be a total scoundrel, while an utter failure might have been a saint.
The same is true for civilizations. Too often, we make the mistake of judging a civilization by its economic, geopolitical and military power. Just because any civilization has been at the top at any point of time it cannot be said with certainty that it was moral, intelligent and efficient. History tells us that civilizations which have the characteristics of scum often become world conquerors and attain economic prosperity. There are numerous instances of civilizations with high culture getting conquered and wiped out by barbarians who go on to leave their own barbaric imprint on the future generations.
The character of a civilization cannot be judged based on outcomes. The origin and development of all civilizations is shrouded in mythology, lies, propaganda and stories which make it impossible for us to take an objective view of history.