Friday Why: Why doesn’t the Berenstain Bear family get to have names?

In the Berenstain Bears series, why are the main characters named only Papa, Mama, Brother, and Sister? The other characters get real names, like Freddy and Honey and Counselor Bob and Dr. Bearson (not the most creative names, but still, they’re names). And its not just that family calls each other Brother, Mama, etc – everyone does. It always bothered me, and I never thought up any explanation, let alone a reasonable explanation. Thoughts, anybody?