Keep in mind the intended audience of this dub. It's an English dub, aimed at English speaking children. They have no concept of the 'correct' way to pronounce Japanese names. For the majority of these kids, what they think of as correct will be whatever they hear. In fact, the anglicized version of saying Naruto will sound more correct to them, rather than a pronunciation that contains sounds foreign to the English language. The only reason it bothers us is because we're used to the subtitles, and we're used to hearing spoken Japanese. It makes sense for them to anglicize the Japanese words to make them easier for their audience to hear and pronounce.