I agree with you. Usually when you work with great programmers, you will be exposed to great code as well.
But sometimes, I have also seen that even when exposed to great code, it might not be evident to someone that it is truly great, without the accompanying commentary by a programmer on why it is great.
I learnt a ton of stuff about programming when modifying the code of the linux kernel for an Operating Systems course. Fixing bugs in a huge code base requires inherent understanding of where things are in the code and how they are connected. And it's during that process that you gain an understanding of how to handle complex things : by making them simple.