I said this before, but it is inspired by a lot of things from Watchmen as Watchmen was inspired by DC Superheros in general and its take as to how it would appear if superheros exist in the real world. So it isn't that shocking at all that Snyder wanted to do the same for this DCEU. Even his his own words he said "it's the Watchmen in him". That said as I said before, while Dr. Manhattan was growing further detached from humanity, Superman embraces it more to the point of willing to sacrifice himself to save it. While Rorschach was uncompromising until the fatal end, Batman ended up compromising and actually believe in hope for mankind which be basically told Diana in the end. While Ozymandias was the supposed "villain" doing everything to same humanity from itself, Lex Luthor was the villain doing everything to ensure his own selfish satisfactions. The themes expression social climate and theology are similar but the motives and their overall conclusion is vastly different. The sacrifice of Superman put humanity into the belief of themselves sacrificing for others in order to do good as shown in the funeral scene while flowers was place on his fake coffin. The movie is VERY different but have the same vibe as that to Wathcmen due to make a serious movie comparing real life situations that reflects our society at large. As of right now we are in a holy war whether we like it or not to where you got half the country or even the world trapped in religious terrorism and xenophobia. Superman is an alien which symbolizes the foreign people here in the United States that are viewed with discrimination because people fear what they don't understand, and hate what they can't conquer. Lex Luthor represent the latter.