That’s silly, There is nothing disingenuous about Bruni stating something that he has studied and believes to be correct, regardless of where he went to college. You are assuming either 1) he can’t possibly be objective, or 2) he’s lying, but you have no evidence of either of those things. There is nothing superior (or inferior) about someone that used their bootstraps to climb out of Appalachia than means that they are the only ones who have moral or intellectual standing to study this particular subject.
I say this as someone who generally disagrees with Bruni and thinks that the elite schools do provide a better education and much better options after graduation than other colleges.