I’m currently a Naval Flight Officer/Senior Evaluator/Mission Commander, and I’d have to disagree on a couple points here. The job is all about responsibility. The days of the rogue pilot who doesn’t adhere to some sort of notion of responsibility are long gone. You may have the oddball here and there, like the idiot Buff driver who crashed his plane at the air show, but overall, the services are looking for aviators who can lead. This requires responsibility. You aren’t going to make it through flight school–API, primary, intermediate, and advanced, without some sort of responsibility getting ingrained into you. You aren’t going to succeed in your first command as a flyer without it.
As for getting pilots from the Academies, well, they’re (arguably) the toughest way to get into the military. You have to be able to handle tough classes and absorb a lot of information quickly and be able to regurgitate it quickly (and I’m basing this off of the Naval Academy–not sure how the AF Academy is, but I’m guessing that principle applies). You have to be able to thrive in a military environment and operate well under large amounts of stress. These are all critical skills of being a pilot. In addition, the academies have strict minimum requirements for math, which doesn’t apply for some ROTC/OCS folks (good math skills are a big plus for aviators). Why not give the academies the first picks of the litter?
And generally speaking, you have to give the pilot a lot of responsibility. This is why you have plenty of pilots who aren’t considered “great” sticks still advancing to command positions. You also have to consider, as has been said, that many pilots will be commanding missions of multi-crew aircraft, and he’ll be in charge of every aspect of that mission, to include deployments, tactical flights, mission preparation & briefings, post-mission reports, debriefings, etc. Try doing this for a 24-crew aircraft for a multi-month deployment to a remote forward operating base. Very demanding. The flying monkey skills are completely secondary at that point. You need to be responsible and you need to make decisions based on the big picture–understand the current military climate, the tactical environment, understand world events, understand your target country and their practices, understand military regulations and the chain of command, and understand how to lead, motivate, and direct your crew. You rarely see enlisted guys with that kind of broad expertise–usually their skills are more focused and deeper in that focus than an officer’s.
Now, you do have the warrants in the Army and (now) Navy doing pilot work, but AFAIK they’re very dedicated to flying-only/training duties and not in charge of anything more than operating the aircraft when directed. There is a reason their numbers are few and far between in the Navy. As for the Army, I can’t speak.
It’s hard to get all the way through ROTC/OTS/OCS/Academy without some measure of responsibility or at the very least, the recognized potential for it. And, your statement of “All you need to become an officer is to have a degree in anything” is way misguided. If my post sounds at all snarky, it’s because that line pissed me off. At least, that’s my $.02 from this side of the fence.