Most officers are products of ROTC, and accordingly, most generals are products of ROTC as well. That said, tradition is very important to a profession, and the service academies are an important part of that tradition.

I do think there is some merit in the points Ricks is making, but that is no reason to act on them. It wouldn't hurt though if more officers were offered the option of pursuing a civilian degree in lieu of attending a service college. Diversity usually makes an organization stronger, and diversity of thinking is essential to keeping an organization fresh. At the 20 year mark, the Darwinian effect of the OER process has narrowed the intelectual gene pool down to a group of people who are far more similar to each other than they probably realize. Sending some out to mix it up with the civilians also helps keep the populace aware of how sharp, professional and dedicated these men and women are and keeps a human face on the military.

I don't think Ricks is suggesting that PhDs make a better general, I've never met a Colonel who was not capable of earning one, so it is a fairly irrelevant observation that he makes rather than a main point in his argument. (And off course most current military leaders went to a war college...its a pre-requistie. Kind of like noting that most Doctors went to medical school)

Anyway, if you focus on his point over his argument and recommendation, it has merit.