Well, the answers are simple. Congressmen and senators, and sometimes presidents (Orion was George W's baby), demand that NASA spend money on stupid shit that NASA doesn't actually want to spend money on, and also demands that NASA spend that money in specific districts around the country to maximize the dollars they claim they brought to their district while minimizing NASA's efficiency.
It is not just that. [0] New Horizons was almost scrapped by Gorge W because of JPL lobbyist that where trying to bloat the project. Where APL was dramatically below and checked all the boxes.
It is also the lobbyist that push bloat to make more money.
I'm making the case of corruption from the top down with politicians, lobbyist are their financial backers. Either through donations or insider trading.
