He allowed Freeza to power up to 100%
He could have killed off Dr. Gero before he made the Androids
He chose not to go SSJ3 against Vegeta to save his ego. He would have beaten him easily and Buu wouldn't have hatched.(I'm a Vegeta Stan and hate saying that one)
He said he may have been able to beat Fat Buu in SSJ3 but wanted the kids to do it instead.
The last two got everyone killed and the Earth destroyed..
And most of those decisions actually are the result of his Saiyan desire to test his strength.
And truthfully he may have told everybody that he wanted to stay dead because he was trouble to the Earth, but in reality he found strong fighters in the afterlife to fight.