The first bullet-point ("People often take aggressive postures that lead to mutually bad outcomes even though mutual cooperation is mutually preferable.") is not backed up by the source, is incorrect, and if it was correct it would be a finding from psychology not game theory.
I believe (not an expert) it is more important to minimize losses that to maximize wins in game theory (cold war roots). Viewed in that light most game theory results are, in fact, extremely intuitive.