Re: I'd rather see NASA do the work
NASA always had private contractors doing most of the work. Grumman built (and designed I think?) the lunar module, Boeing built the Apollo capsules. NASA designed the Saturn rockets, but put it out to various contractors to build them.
SpaceX have been the lowest bidder on the contracts they've won - and produced working hardware, so far. And they've certainly done better than NASA on SLS - though with a quick search I'm still not sure how much of the design of that is NASA and how much is Boeing.