In the Catcher in the Rye, why are the parents' perspectives not given?

I have to write a 5 paragraph essay on this question. I think that it's because they are only important as "Holden's parents" and not as individuals by themselves. Plus, I think they would distract the reader from connecting (and feeling sympathy) for Holden Caulfield. However, I needed better and clearer body paragraph topics. Please. Help.