In the meantime, my friend Brooks Marmon, who runs the Africa in DC blog has a great post on Beltway insider Hank Cohen and his frankly mindless read on the South Sudanese state. You can read the piece here.
I would only add that it is very rare that former colonial holdings benefit from the infrastructure handed to them by their former colonial masters. With the exception of the oft-cited railroads and democratic institutions in India (which we will soon see, is a questionable example), rarely has colonial investment in infrastructure given anyone a leg up - often this infrastructure is damages or destroyed upon the exist of said colonial power. Even in India (as was well documented by Stanley Wolpert in his excellent "Shameful Flight: The Last Years of the British In India" among others), British disengagement had horrible outcomes: leaving behind mountains of dead, political instability (likely setting in motion the eventual fracturing of Pakistan and Bagladesh from India), heavily damaged infrastructure, regional instability stretching all the way to Singapore and the active undermining of the new Indian state before it even came to fruition - dramatically undermining Nehru and the Congress Party's ability to govern.
In the end, it reminds me of the words of my undergraduate Southeast Asian History Professor (in a survey course on the Philippines), who pointed out that with colonialism, even when one can cherry-pick a few good outcomes of that colonialism, the base relationship remains one that is abusive and thus the underlying legacy can only be assessed as such.
It is amazing (though not at all surprising) to see the type of discussions about Africa as critiqued by Marmon in the above post persist on the Beltway.