That is a fair point. I will reiterate that I agreed with the original poster and was positing what the counterargument presented from the courts/3 letter agencies would be.
We'll never see that counterargument regarding the cost of engineering FBiOS, since the case was withdrawn.
[Edit: we'll never see it because I believe that the FBI will not likely go after Apple again, specifically because they put up a much more forceful fight against it than the FBI ever thought they would. Admittedly I'm speculating, but I don't think I'm being unreasonable]