Because he's good. He literally spat out the bad parts of himself. Goku isn't overall pragmatic, but when the situation is in fact an immediate issue, he will be pragmatic. Buu at this point is just a potential threat.Yes, how is this Boo any less of a potential threat than Cell is? With a wave of his head tail, he can kill everyone too. Is it because he helped them out once? By that logic, Vegeta should be a dead man in the Cell arc. He not only didn't help anyone but he actively hindered and escalated the problem of beating the Androids. Nor is he a good person by this point and admits several times openly to everyone that he wants to murder Goku once all of this is done. Why isn't this new, pragmatic Goku, snaping Vegeta's neck?
Of course it makes no in-universe sense BECAUSE it was a retcon. He wrote the fight against Vegeta believing Vegeta and Goku were on the same level, then when he needed Goku to be able to fight Buu, he created Super Saiyan 3, then he later said he SS3 Goku could've defeated Buu even though he had already said he couldn't. Since when has Goku created an issue that he didn't INTEND to face? He has done reckless things before, but never without intending to face it later on (e.g. letting Piccolo and Vegeta live), but now he lets Buu get created so others can take care of it? That's just inconsistency in the writing, not Goku being a dick. Goku couldn't have just used Super Saiyan 3 to defeat Buu because him being able to defeat Buu as SS3 was a retcon. You sound incredibly angry over a fictional character.A retcon that makes no in-universe sense and makes Goku look like an asshole any way you slice it. Before the retcon, he says "he's dead so its not his business to interfere with the living world!" Okay, so why is he at the tournament made FOR the living? Why is he involving himself in the initial Babidi stuff? That's not his problem, that's a problem for the living, so why didn't he just piss off back to King Kai then? So, it's Goku's right to interfere in a tournament for the living, escalate a problem for the living, but not his duty to fix said damage he's done to the living?
After the retcon, Goku's still a shit head because he could've just used Super Saiyan 3 to beat Vegeta or Fat Boo. He admitted to being to do the latter and thus the former by extension. Instead? He's like "Nah, let the kids handle it!" What?! The kids aren't the one's who made Boo come out, it was him and Vegeta. Also, this is a Goku who pretty much admitted his stupid Saiyan logic makes everything worse at the end of the Cell arc, so why is he listening to this stupid logic again after it got him freaking killed the last time?!
The tournament is just for fun, now you are looking for things to complain about.
Even though you acknowledge the retcon you continue to judge his actions as if there's not retcon! He wasn't having fun with Vegeta, he was trying his best to stop him, but that was later retconned, but continue dismissing that simple fact.
That is NOT being a plot device. He's not acting out of character to facilitate story. He's acting in character when he does reckless things like allow Vegeta to live or allowing Dr. Gero to finish creating the cyborgs. He's a character that loves fighting above pretty much everything. If you ardently hate the main character this much, why do you watch the show?Goku is a plot device who walks and talks and does things to make the plot move forward. Any time he does something even halfway mature, it gets buried under more stupid Saiyan logic which he himself has admited is a problem for him, TWICE! and he does nothing about it.
