“They don’t have a sense of the institutions and the culture, so they’re less likely to exercise insightful or determined oversight.”
That's an unsubstantiated opinion. Here's another: "They lack a pro-military bias, so they’re more likely to exercise insightful or determined oversight.”
Fewer are doctors, yet they pass health care legislation. Fewer still are farmers yet they pass a farm bill every year. Precious few are truckers or pilots and they oversee transportation. One does not have to have experienced something to understand it or oversee it.