Yūgi's BM;35239613 said:
Gokuu let Piccolo live after the Twenty-Third Tenka'ichi Budoukai because he didn't want to lose a rival. This after the guy had killed hundreds, including his friend.
It's not the same Piccolo though. It's his son. And up to that point, he hasn't actually killed anyone. He even made sure not to kill anyone, because he didn't want to get disqualified, until he faced Goku.
He then let Vegeta live and escape the planet, right after he had been complicit in killing his friends, tried to kill two of his friends, his son and himself, to say nothing of everyone else on the planet.
Definitely one of his more reckless decisions. But Goku is also portrayed as a person who doesn't want to kill anyone who's defenseless. During the whole battle, it's not like Goku was making sure not to kill Vegeta. He went all out, and had the Genkidama actually killed Vegeta, I don't think Goku would have mourned losing a rival.
This is the same guy, who knows when a situation is hopeless, decides to go down with the enemy, if that's the only choice. It was the only option to beat Radditz at the time.
Gokuu then gave Cell a Senzu. The guy who was trying to kill him and everyone else on Earth.
Knowing full well his son could kill him with little to no effort. He even urged Gohan to finish it quickly, and was shocked when Gohan, basically power drunk, wanted to make Cell suffer first.
And he kept holding back against Vegeta and Buu, too.
He was stupid when he fought Vegeta, because he tried not to hurt his pride, by revealing that he had surpassed him yet again. But I understand why he didn't go all out against Buu. And the way Toriyama wrote it, made a lot of sense.
Goku only had 24 hours on earth. Using the power of a SSJ3, cut into his time. He might have been able to beat Buu, but there could have also been a chance of his time running out before he beat him. After his short battle with Buu, he only had a few hours left to remain in the realm of the living.
And if he had managed to defeat Buu, what then? He'd have to go back to the afterlife, and if another enemy threatened to destroy humanity, there'd be no one around powerful enough, to take on the threat. So instead of taking the chance to defeat Buu right then and there, he decided to teach the children instead. Teaching them the Fusion Dance, that would give them the power to defeat Buu.
The safety of others is ultimately not on his mind.
I don't disagree that he's reckless. But I think Super just dials that character trait up to eleven. And if he didn't care about the safety of others, he wouldn't have been so angry when Majin Vegeta kept blowing people up left and right. He cares about a good fight, but he also tries not to get innocent people in harms way.
To me, Radditz, Cell and Buu are the better examples of his personality. He died to defeat Radditz, he let Gohan fight Cell and urged him to finish the fight when he was severely wounded, and he taught the children the fusion dance, so they wouldn't have to rely on him anymore.
So yes, Goku loves to fight, but he also knows where the line is. He keeps letting villains live, but he's also constantly portrayed to have a childlike innocence, so he doesn't like to kill opponents that have been beaten.
But despite all his reckless behavior, he never got out of his way, to run all over the plays, egging people on to fight him.
