I don't think being that cynical is warranted here.

1) The requirements aren't levied by congress. They are created by NASA civil servants who are usually the technical experts in a particular field. These aren't people who have much of any interface with lobbyists.

2) A lot of the instances where it's not worth it to suppliers isn't because they are being boxed out by some industry giant clamoring for some giant contract. It's usually closer to "it's not worth our effort to overhaul our manufacturing process to meet requirements so we can sell NASA a $70 teflon seal." The giant corps have little desire here either. But being a big manufacturer is sometimes correlated with having a more mature manufacturing process that meets specific standards.

When SLS was designed by congress they specifically wrote the requirements so that the Shuttle contractors would continue to receive contracts.

Those drive some of the main contractors (like Aerojet Rocketdyne) but not all those others in that protracted list. Those are selected by the supplier quality process defined by typical civil servants, not Congress.

That's true but not where most money goes. And for a lot of these things there are just the same legacy contractors.

This was about how that long list of suppliers gets selected, not about how they make money. If you look through my previous posts, you’ll see I acknowledged most of these suppliers aren’t on the list to make a ton of money from NASA, and that a lot of suppliers don’t even attempt to make the list for that very reason.

There’s already enough corruption in govt, we don’t have to make believe it’s in places that’s it’s not.