I struggle with this too that Michael is Vito without the heart because Carmela was the heart "you can never lose your family" and Times are changing

I reckon Vito gets a pass because of the way he is cleverly portrayed, compared to Michael and others
He too was a cold blooded murderer despite his outward nice guy appearances!

He was interfering / destroying innocent people's legitimate business and lives because they won't comply with his demands like his threat of lethal force even in such simple business as the release of his Godson's contract shows where Michael got his cold bloodedness!
The band leader built up Fontane's career but he couldn't benefit when his client became a star

“Look how they massacred my boy...What about the gruesome murders of other families' boys

I reckon Puzo and Coppola cleverly make Vito look justified but he is as guilty as others of committing horrendous acts, cold blooded murders, destroying families

I feel at times Vito is seen through rose-coloured glasses as perhaps because the way Vito is romanticized and portrayed