Nope, no business men necessary to water down the original concept. There were two camps among the developers already, "Science Camp" and "Cute Camp". Will Wright states that the end product struck a "nice balance" between the camps (
see here), but basically the Cutes won. Why this happened is a matter of speculation, but personally I suspect that the Science Camp devs simply didn't find a way to make their grand design actually fun to play. The repeated delays in development, the changes of major game elements even in the late stages of development, and the hiring of Soren Johnson in a pretty late stage as well, are all pointers that the original design had (unfortunately) failed, and that the devs scrambled to make it work _somehow_. Concentrating on the Cute Camp was then the easiest way out since it allowed them to focus on looks and accessibility while simplifying the non-working gameplay.
That's just my personal theory of course, you'll find others in the Spore forums.