Zimmer doesn't have control over that, studios do. The Dark Knight was submitted as was Frost/Nixon. Zimmer just doesn't care. That's not actually correct. http://www.oscars.org/awards/academyawards/rules/rule16.html
I can hear everything fine. It's stereo sound. That's like saying you don't need Blu-Ray because VHS also has colour picture. I'm not an audiophile, I don't care. You have low standards.