I imagine if some parts could be kicked off as an OSS project, there would be no problem with getting contributors. But for example rockets require a lot of work from a lot of people, but the amount of people who benefit from them isn't particularly big. Maybe their number is only single digit.
Makes me think of how the Verein für Raumschiffahrt had just managed to get some land where they could fire rockets and then the Nazis told them "You've got to stop that, someone could get hurt!" then it dawned on the Nazis that they liked the sound of that.