There's no practical reason we couldn't consolidate primary flight training, and others have said, there was a serious effort at it for most of the early 2000s. However comma truly consolidated training also means the services give up some degree of control over their syllabus and training philosophy, which nobody wants to do. In practice, CNATRA and AETC still kept hold of the wheel for their respective units and the "joint" training squadrons really wound up just being Navy squadrons with some Air Force guys assigned and vice-versa. I recall some IPs grumbling about having to "un-train" the Vance graduates when they showed up at the Advanced VTs.
Personally I think cross-pollination is healthy and it never hurts to learn how the other guy does things. My VT-10 on-wing was a KC-135 major and it was interesting hearing him talk about how the AF runs (plus it kept him talking on long XCs and not asking NATOPS trivia). But the ostensible purpose of joint training - efficiencies, etc - I don't think ever really came to fruition.
Personally I think cross-pollination is healthy and it never hurts to learn how the other guy does things. My VT-10 on-wing was a KC-135 major and it was interesting hearing him talk about how the AF runs (plus it kept him talking on long XCs and not asking NATOPS trivia). But the ostensible purpose of joint training - efficiencies, etc - I don't think ever really came to fruition.