He's technically right. The dub of Dragon Ball does aim it towards American children (because in 'Murica, a protagonist apparently isn't allowed to be selfish and has to be "the light and hope of the universe" or some **** )
In the original, he's pretty selfish in some aspects, purposely putting the universe at risk just so he can fight strong opponents, and when he turns super saiyan against Frieza he doesn't use that self-righteous ******** speech of being the light and hope of the universe, he just says he's a saiyan from Earth and is there to take revenge.
Well, i knew while dubbing they had to change some things to make the show more ''funny'' like adding silly jokes and puns, but this?, well, actually i'm ok with this, since it at least is something that makes the character a little cooler.