The explanation that was given was that it would be too dangerous for him if people were to learn that he was the Fourth Hokage's son (volume 47, episode 440).
Never mind about Konohamaru.
Never mind how people apparently quickly found out about Naruto's other secret, that is to say his connection to the Nine Tails, and gave him hell because of that.
Never mind how he got to keep his "Uzumaki" name, which should be fairly recognizable (they have the clan's crest on their uniforms) and narrow things down quite a bit (not that many survivors, but there was... yeah, the Hokage's wife... who was pregnant back when he would have been born, come to think of it!).
Heh.