Not even accounting driven. It's MBA driven.

Accounts ask how much things cost and go from there. MBA's figure out how much things need to cost to make their spreadsheet work and tell you that's what you get.

Which is what happened at Boeing. They told the engineers they were going to develop the 787 for half the cost of previous models (we are very very smart). And it took twice as long and cost twice as much. Given that they couldn't afford a clean slate redesign of the 737 even if they wanted to. The result is the 737 Max which will cost them more than a clean redesign would have.