That may be how Kids WB presents him, but he was just as Atom, a robot created by Tenma to replace a dead son (See Episode 6 of Fansub, anapan's ftp; see
Astroboy.jp Atlas page). Tenma's client wanted a robot that could pass for his son, so that he could take over the family business when papa retired. However, this man was no better a father to his son, than Tenma was to Tobio. He just 'did' not have time to spend with his boy. Tenma probes the dead boy's mind for memories so he can make a robot that behaves just like the boy he is to replace. Finding an interesting subject, Tenma creates a robotic body that can accomodate the unfulfilled desires of the boy. Hence, he creates a robot that can transform from a human-appearance to a fierce and violent flying robot.
This makes me wonder about whether I was right in thinking that Kids WB is trying to make a whole different Astroboy from what Tezuka has made. -- I just checked the hero's bio at
Kids WB Astroboy pages (requires apple Quick Time), and it does say he tries to reason with his foes before he fights them.