Does it really take an "engineer" to find a trouble-spot and fix it ? Why do you need a billion-dollar fund to grab engineering talent to do what the highly-paid leaders of, say, airports, are already supposed to be doing ? If they can't figure it out, isn't there a whole industry of consultancy firms that send "analysts" through your organization to do the same thing?
If this sector is so profitable, will it cause the same crisis that privatization of hospitals did to healthcare ? Say "Global Infrastructure Partners" expands and "buys" JFK, ATL, LAX, just like private healthcare bought all the hospitals. Now they can start jacking up their landing fees (each year) until air travel becomes unaffordable. What's to stop them from turning this into the ultimate regulatory capture ?