With your stats, accomplishments and school list, I'm willing to suggest that it could have been a combination of "small" things that led to this result. I happen to know that all the CA schools (especially the public schools) are motivated to admit CSU grads.
You mentioned essays. Sometimes, it's the optional essays that can sink an otherwise strong application: things like applying as disadvantaged when it might appear otherwise to some evaluators, photos (or interview attire) that are too casual or not following recommended number or type of LoR's. It doesn't sound like you wrote an "ortho or nothing" application, but those with a strong interest in a sport need to be careful of avoiding that appearance.
Re-write everything if you don't get off a waitlist. ...and work on interview technique.