It isn't "big picture" rational, but it is rational in a myopic way. Most managers in a company are only responsible for their own little kingdom and will care

It isn't "big picture" rational, but it is rational in a myopic way. Most managers in a company are only responsible for their own little kingdom and will care little about the rest or any overall whole-company picture. Only the highest-ups are responsible, accountable and incentivized to care about the whole.