Wouldn't have anything to do with those big airplanes that hit the building, would it?
You don't give the engineers much credit do you? The design specifications included the structure should withstand the impast of a B-707. The reason for having a sprinkler system was to protect the structure from a catatrophic event, such as the impact of a jet aircraft. Redundancy in design would have negated the impact of the aircraft, in my opinion.
Please consider that three years of planning was but in the mission to bring down the towers. If that is the plan and the mastermind of the attack is an engineer, is it a stretch to consider that the plan included sabotage of the sprinkler systems that helped minimize the destruction of the 1993 attack by the same people? These folks learned from their first failure.
I understand your point but it is almost the same as if I told you I hit a tree in my car at 40 mph and the seat belt failed and you responded, "Wouldn't have anything to do with hitting that tree, would it?"