Kind of reminds me of the University of Utah stadium... it was a lot smaller, but very open and easy access in and out. When I went to school there I thought it was a beautiful stadium and bare bone appeal felt like you were there before you even got there, open to the outside a backyard feel... rather than a closed off arena.
Like with Levi's, the bare bones exterior is for looks stability, and safety.
A lot of you guys don't seem to like it, but I think it gives a clean and efficient look that doesn't bend to architectural trends. It also kind of reminds you of a suspension bridge, which is an iconic symbol of the Bay Area. If you don't like it, you don't like it, it's subjective. I do though.