First off goku verbatim states that he cares not even if his kids are born, Something that even vegeta of all people finds digust in.
And it gets even worse when you consider that piccolo has even presented better care for goku's own family then goku has with him watching and taking care of pan's wants with goku not even knowing what those wants are.
Piccolo had to explain the nature of goku's son to goku.
Piccolo in the same panel was willing to lay down his life to help gohan when his own father would not and he was worried sick about the sick about the boy when he his father was not.
Not only that but his increased the chances of gohan dying versus cell by giving the bio android a senzu bean which made him recover from the damage that goku gave him.
Overall in the cell fight alone, He risked the life of his son,helped the person trying to kill him and didt even understand the behavioral patterns of his own kid when a alien from a another could. In any universe this would make goku a bad father and the facts just do not present evidence of him being at all good parent
If were including material not from the cell fight, He has put the universe within danger by suggesting an omniversual tournament which risks the erasure of failed universes,He has verbatim stated no care for if his offspring are born and knows less about his grand daughter then a alien who tried murdering him years back