The Navy wants the Space Force under their command?
I hadn’t thought about that. Very interesting idea.
Only the Navy has experience with long missions, isolated crews and non-existent supply lines.
The Air Force would be good for quick near Earth missions, they have a LOT of experience with missions lasting a few hours, and quick return to base for dinner and refueling.
Any self-sufficient mission lasting months? Not so much...
Occam's Razor