I think it's not so simple with Jack's 'good' childhood. When Horner remembers his past we see some old dirt wagon where little Jack tries so hard to perform, indifferent parents and failures. I think Jack went for a very long way to successful pastry owner and crime lord thing. Also it's pretty strange how much baker dozen cares about its work and how high they motivated. If Jack completely doesn't care about personal we would not see such behavior from them.
I think It’s funny to see history, repeating itself in a way before villains were just evil, and we wanted them to be understandable. Now they’re understandable, and we just want them to be evil.
