So if no (or few) aviators want to achieve command at sea, where do you suppose the Navy gets leadership that has familiarity with flight ops and air capabilities? We learned the hard way in WWII that we need senior leadership who understands this aspect of naval warfare, and this is even more true now than it was in the 1940s.
What I think Brett has been alluding to is that the Navy needs its most talented officers to eventually move out of the cockpit in order to maximize overall naval warfare effectiveness. This isn't about any individual's desire to have more fun flying, and everything to do with putting people with the right background in the right positions. If you stick around for 20 years being a super-LT, you're blocking a spot for someone who will be willing to step into those bigger roles. Theoretically this could be properly managed, and thus could make a guy like you more happy, but what is the payoff for the Navy to go through the hassle?
I don't think there's anything wrong with liking your JO job, but I would hazard a guess that the animosity toward the "I just want to fly my whole career" mentality stems from senior leadership believing that they have explained the above to said JOs in much greater detail, and yet they still stubbornly refuse to accept/understand their role in the organization.