OK. two points to make
1. Any civillian contractor working on a military contract has to deal with the fact that every three years or so the customer (i.e. the officer he has been dealing with) gets posted and someone new comes along. That someone new has their own ideas of what they want, and wants to know why decisions have been made the way they have. This inevitably leads to changes in the specification.
2. Any change to the product, at any point in the process, requires time and money to implement. The figure I get quoted on a regular basis is "a thousand bucks just to change the drawings". That drawing change could be as simple as changing the part number, or sticking a label on.
So, from point 1 above, any new "customer" who wants changes will delay the project and cost money.
And believe me, in order to do a thorough, professional job and not leave the company open to liability if something goes wrong, we the engineers have to take the time and money to get it right. BAE seem to be singled out a lot recently, but I reckon a lot of firms in the same line of business are saying "there but for the grace of god..."