Part of it is leveling employment.  The government is fond of large projects that require multi-year ramp-up and ramp-down and massive up/down swings in employment need. 

Suppose in 2019 you're hiring every rocket scientist in town because of the SLS.  2023, you lay them all off because the project is done.  2025, you need them back because China is getting frisky, and the ASAT capability in the SM-3s *needs to actually work*.  

Only you go to get your rocket scientists back who really know that system, **and they're gone**.  They didn't wait around for you to hire them back.  Some went to be data scientists for Amazon and got poached by Google and live in the Bay Area.  Others work for the Texas oil companies.  Others for FMC in mining out of Salt Lake.  A few emigrated and work for ESA, those are the only ones whose skills haven't rotted out.  

The Chinese, meanwhile, had created US subsidiaries which did everything possible to break up your brain-trust and drag it off to other employment centers, encouraging the younger ones to settle down, so they are unwilling to move back to Seattle.   

The braintrust is gone.  You can’t exactly *draft* them... so now you have to staff that department up from scratch with green weenies who don't know the systems at all.  

This way, the government tells management to treat SLS as a D-list project.  When project X dries up, you dump them into the SLS, which has forward motion because your team has nothing better to do.  When the "Fix the SM-3" project pops up, you tell them to shelf the SLS and come work on the SM-3.  Once that is managed, back to the SLS.

This also lets you cheat.  Project X could be the 737 Max.  You're not supposed to subsidize commercial airliner divisions, but, heh heh... 

This sort of thing has been done before; this is how Boeing got into the light rail vehicle business.