I trace this "lack of threes" in science (if indeed it was a truely successful motivation) to be traceable to Boole's WORDING of his "Rules of Thought" which is only narrative to symbols of the order x=x^2 and not even that at that much. x=x^3 is not even logically attempted in general.
I have mentioned this in passing before but I cant seem to find my reference on EVC. Ill look again but the content is the same.