A Middle Eastern Excuse?

In class we learned about Rabbi Tsarna's view on Yaakov and the bechora. What Yaakov did wasn't bad because that was accepted and the way of life in Middle Eastern societies of the time. Does this strike you as somewhat of an excuse? I mean, haven't we learned thus far that everything ethical monotheism stands for was revolutionary to the time? For example, perek aleph is a very organized, evolving, purposeful account of nature. It describes the creation of nature by G-d. G-d is in control of nature. This is revolutionary because other societies were so scared of nature. This is why this 'excuse' was a little disappointing to me because I loved seeing throughout Sefer Bereishit how the nivchar and ethical monotheism really changed the world. However, you may consider Sade's blog where she mentions Yaakov was only a child! Doesn't every child want to have more power or attention than their sibling? I mean that does seem pretty normal. In psychology we learned all about the Oedipus Complex when discussing Freud. Does it really seem so bad that Yaakov was fighting for some attention from his father? Or, as the nivchar, was he supposed to know and do better? What does everyone think about all these questions? I would love to know!