I think that statistically speaking, the odds of making the kick for one point are about 95% or more versus the chances of making the two point conversion of something around 35%. Just based on the 'odds', it makes sense to kick because over time you will score more points. However, if your are one the nation's best offenses, as Oregon has been in recent years, then your odds of successfully getting in the end zone from 2 yards or so are much better than 'average'.
Based on that, I would say, it seems very logical that Oregon SHOULD go for two on all extra points versus 'below average' opponents as their odds probably increase from 35% to 75%. I would say that Oregon probably averaged nearly 5 yards per carry just running the ball against us. And average per play much above 2 so logic indicates they should be successful, over a large number of tries, to convert more than half and therefore score more this way.
I also believe that Oregon's coaches most likely were very concerned that they would NOT score at will against our defense and therefore it seemed wise to attempt to score as many points as possible once in the red zone.