You might want to think of this story as a contemporary "Young Goodman Brown." Chris, perhaps the supreme idealist, has never been able to see him as just another man, much as Brown held his townspeople in such high regard that he could not accept them as complicated moral beings. Of course, part of this is Joe's fault since he did violate a basic moral principle. But Chris always expects more of people that he, perhaps, has the right to. The Bayliss neighbors have been "contaminated" by his idealism; Sue is very clear about what she sees as the damage his vision had done to her husband; she is the realist who knows that earning a living is what it is about.
Chris needed to understand that his father IS a man; expecting more than that can lead to trouble. I suspect that if Chris had been able to accept his father even with his failings, Joe may not have committed suicide. Who knows. But I think Miller clearly suggests it as a possibility.
One of the central themes of this play is the relationship between father and son and how sons cope with evidence of their father's misdeeds. Chris, having found out the truth about his father Joe and his unethical decisions to obtain lucrative government contracts, expresses to his father the disappointment he feels with him. Although he states that he didn't think Joe was a perfect person, he did think that he was better than other men morally. His love for him as Joe's son has blinded him from seeing the truth of Joe and his actions during the war. As he realises the truth about what Joe has done, he has his image of his father irrevocably smashed and is forced to accept the consequences in denouncing his father so justice can be served.