Contrary to popular belief, Son Goku does has a character. Not a deep or complex one mind you. Goku likes two things: to fight strong guys and, to a slightly lesser extent, food. That first major character trait had ended up being the cause of a great number of events throughout Dragon Ball. Hell, two thirds of Dragon Ball Super came as a direct negative result of Goku’s innate, uncontrollable lust for battle.
Toriyama’s Goku isn’t a hero in the classic sense, there no doubt he’s a good guy, but still a selfish one who readily endangers those around him if it gets him what he wants. With Super still seared into my mind; The Goku seen in Dragon Ball GT, thus far, he doesn’t seem like Toriyama’s Goku to me.
A Richard Wood Text Adventure 