On that spreadsheet the TDO never changes no matter what moveset you give the defender.... which isn't right...
Scizor's Steel sub-typing allows it to double-resist Exeggutor's Grass moves AND resist its Psychic moves, while Pinsir is pure Bug so it only resists the Grass moves.
EDIT: Sorry, misread the question, thought you were asking specifically about Exeggutor. But the point still stands that Scizor's DPS is almost as good as Pinsir's but it's got bonus Steel-type resistances. Pinsir's extra 2 ATK is outweighed in most situations by Scizor's typing and extra 10 STM, imo.