Goku is an absent father, not a bad father. It's like calling solders bad fathers for being overseas and choosing to go on another tour. Gohan was kidnapped while he was dead, and he chose to go save his master Piccolo by going to Namak. Considering Goku's adopted father Gohan died when he was still a child, forcing him to make his own way in the wild until Bulma came along, it's no wonder Goku is an absent parent. Then again the whole of the Sayian race sent their children off to planets on their own on eradication missions.
Goku was with his son everyday until his Brother showed up one day, then after he returned to earth for the 3 years while training for the androids, and spent a year in the Time Chamber to prep for Cell. Meaning Goku was only absent while he was dead, and then while he was learning to control his strength and getting the instant transmission.
Ozai was going to kill his own son for the opportunity to be the Firelord but his wife chose to do something, that was never explained, the result being banishment to save her son's life. Then, for speaking out against the senseless death of his own nations men as part of a war tactic, Ozai scared his son and banished him.
Ozai wins not only worse father but also worst person.
I'll end with Dragon Ball GT never happened, Toriyama had almost nothing to do with that pile and only came in at the end to save what was left of his story. When Goku was killed by cell that was the end of it. No Goten, no Videl, no Uub, no Majin *, no fusion.
Anime sucks read the Manga.