The US Government (Department of Defense and "Intelligence Community") doesn't have a lot of choice. They've let the already incestuous aerospace industry contract to about 4 main companies, and those 4 don't compete with Boeing in the passenger aircraft space.

Boeing probably hasn't had a "farm team" of design engineers for 20 or 25 years, now. Designing a new passenger jet isn't something that comes around more than once in a lifetime.