DT, I think you hit the nail on the head. Respect or lack thereof shown to Vito and Michael was a function of the eras in which they reigned. As the novel states, Vito made sure that his actions were viewed as personal by those who received their benefits. Micahel made no such effort.
"Generosity. That was my first mistake." "Experience must be our only guide; reason may mislead us." "Instagram is Twitter for people who can't read."