The entire middle third of the comment is the standard engineer's fallacy that because the laws of physics are absolute and not relative, people's values should be also, and all conflict could be avoided if people were just rational. The main evidence offered is this aside about "science" "proving" the non-existence of god, so its fallaciousness is highly relevant. (There's also the fun of pointing out a fallacious and therefore irrational arugment in support of being rational, I'll admit it.)
Every college student in a technical major who has to take a humanities class for general ed goes through this phase, it's understandable. But it's just as important to grow up and leave it. Values are not rational, but that doesn't mean you get to ignore them.