Based on Billie’s mother sharing her conversations with her husband, that part of him would never continue to hold him as a salesman. He and Billie are similar, both have rich inner worlds that have a difficult time synching with the world at large.
Her father loved her and understood her. Her life would have been do much nicer full of love.
After reading all of the responses up until now, I find that I agree most with Carol Ann. Billie idolized her father. He was fun, nurturing, attentive, etc. all sterling qualities in a parent, but I wonder if her mother was the parent doing the heavy lifting, i.e. the things that were also necessary, but are behind the scenes. Who can say If Billie’s father had lived how she would have viewed and compared her parents as she got older and hopefully matured emotionally.