That's just not good enough.
Did he have great moments? Sure.
But many of those great moments were cancelled out in my mind due to overthrows and bad decisions, accompanied by awful mechanics.
The latter is his biggest weakness. He cannot consistently throw well because his motion is all over the place. There was a throw that was nearly picked where he just stood and threw, using his arm only.

Is it fixable? IDK, I suppose it's up to him. But if those mechanics issues are not fixed in the off-season, I would like to see a new QB. Retzlaff will not lead us to a big 12 championship if he continues to play like this