It's hard not to feel sorry for Fredo. He didn't inherit any of Vito's characteristics. He was weak,stupid,incompetent, virtually devoid of any street sense,incapable of the most basic strategic ability,loud.flashy,and given to self pity. In a Mafia family ,these are not good character traits. However,had the Corleones stayed in the Olive oil business,and remained legitimate, I bet Fredo would have had the happiest marriage,the most kids,and been one of the best fathers in the family. The traits that made him a bad gangster are ironically what would make him a good person. Vito getting someone like Fredo involved in the family business, no matter how small the role,was one of the most shameful acts that a father could do to a son. Vito had the means to give Fredo the best possible education, and set him up in a legit business that would have made him very comfortable.