Goku is the face of Dragon Ball, there's no doubt about that, but some of the things he has done over the course of the anime have been far from good. Goku is a pure soul and although he doesn't mean anyone harm, some of his traits are downright frustrating.
It gets to a point where his family and friends cannot deal with his shenanigans but what can anyone do when he always steps to save the planet. There isn't any excuse for the lack of personal development in Goku and maybe he should consider improving himself bit by bit. Nevertheless, here are some of his worst character traits.
10 Looking For Fights
Goku is always on the lookout for potential opponents, challenging almost anyone who can throw a punch. It's hilarious to see his excitement whenever he spots someone ready to battle. The problem here is that he looks for violence. That, in itself, is a very huge problem and some might even term it self-destruction. Goku doesn't fight because he is angry, instead, he fights because he feels a kind of rush doing that.
9 Too Much Training
Goku cannot stay still for a few minutes without throwing punches and training his body. He puts himself through a rigorous routine and his eating habits aren't good, either. He eats too much and trains too much. It's almost as if Goku takes his Saiyan physiology for granted and no one would feel for him if his body breaks down completely. It's okay to train hard but he needs to start taking care of his body, rather than using it like a machine.
8 Overconfidence
Every single time Goku comes up against an opponent, he overestimates himself and underestimates what the other could bring to the table. Vegeta refers to it as the Saiyan pride but there's a very fine line between overconfidence and stupidity.
Maybe it would help Goku to be pragmatic at first and then after having a good look at the surroundings, be confident about his chances. He never learns from his mistakes, though, and it has cost him his life; most notably in the Cell Saga.
7 Doesn't Listen To Anyone
Goku cannot stand anyone's opinions. Chi Chi provides him with so much incentive to become a better father and husband but Goku never listens. He takes it in and then throws it out of his ears. He might be good at giving advice but he surely doesn't know how to take one. Vegeta has told him several times to not take decisions for the whole planet but it is what Goku does. He doesn't care about what others tell him.
6 Not A Role Model For His Children
This is the worst thing a dad would want to hear but as mentioned above, Goku couldn't care less. Kudos to Gohan for not going in the direction of his father and actually stepping up to become a self-dependent man. Goku is not a role model for his children, not only for the violence he so readily seeks but also for his childish nature. He hasn't grown up nor is he matured enough for his age.
5 Putting Himself In Danger
Be it him allowing genuinely evil villains to come back or inviting an attack on himself, Goku always puts himself in danger. In Dragon Ball Super, he took it another level. After the Universe 6 vs Universe 7 Tournament ended, he was sweating to know the real powers of the purple assassin Hit. And he gave him a contract to kill himself. The thing is, he almost died, and yet, he simply didn't care.
4 Doesn't Look After His Family
Even though Goku is loved for his childish nature, some of the fans do not like the way he treats his family. He only ever meets Gohan if he wants someone to train with or when a fight is coming to Earth. That is not how a son should be treated.
The same can be said about Goten, who Goku rarely meets and plays with, despite him being a little kid. He loves Chi-Chi but never spends enough time with her. As it turns out, Goku's family takes care of him when it should be the other way round.
3 Carelessness
Being careless is not necessarily a bad trait as it all depends on what an individual is careless about. Goku is careless about almost everything. The Saiyan doesn't even care about his own life but in his defense, he does step up whenever his family and friends are on the verge of suffering. Nevertheless, that doesn't excuse him from showing a lack of care for every human emotion other than that of himself.
2 Ignorance
Goku's ignorance stems from his inability to understand others. He thinks and sees the world in a certain way, and according to him, that's the only way life should be lived. He should be taking the example of his son, Gohan, who is genuinely one of the most understanding people one could ever wish to meet. Goku needs to open his eyes and at least try to understand that the world isn't as binary as he sees it. It's always about the increase in power levels for him when there are more important things in life.
1 Selfishness
Goku is selfish about power. He no longer wants to be the good guy, he just wants to be the strongest mortal in the multiverse. He arranged the Tournament of Power for his selfish motives. He didn't even show any guilt upon learning the punishment if his Universe lost. Instead, he was excited just because he was going to get more powerful. This isn't a good look on a supposed hero. He should have some moral code to live by and if he keeps going on like this, his loved ones will pay for it.