Why did I do this? Because I love Dragonball, that's why!

I do like that as the translations have gotten better, it becomes more clear that Goku, for all his good qualities, is still a slave to his Saiyan nature. In fact, the Android/Cell arcs could potentially be seen as a deconstruction of the Saiyans: Vegeta ends up jeapordizing the planet for the sake of a good fight and his ego, while Goku's plan to defeat Cell nearly falls apart because he never realized his son didn't enjoy combat until it was nearly too late. Hell, Akira Toriyama's pretty much said that Saiayns don't really do families.

I think that when Toriyama came up with the idea for the Saiyans, he wanted to bring the idea of a warrior race to its ultimate logical conclusion, but that's just conjecture.