Businesses choose to err on the side of either efficiency or control. In the case of our utility infrastructure they have chosen efficiency. Everything being interconnected is far more efficient than the days where a problem in one area can be readily contained and isolated. The downside (control) is that a problem in one area can quickly cascade into a far larger problem had the system not been so interconnected to squeeze the last bit of efficiency out of it. The article even notes that good security at the valve stations is too expensive and not practical. Terrorists thus can more readily exert control over the system at these stations where the utility doesn’t have physical control.
The other old business maxim is: Price, Quality, Service – Pick Two, meaning a successful business can be really good at any two of the the three but nobody can be the best at all three. For example quality and service cost money and so such a business would not be the low cost provider. In the case of utilities, they chose price and quality. The vast infrastructure is a wonder to behold and most of us spend a relatively small part of our income on energy. A focus on service would preclude the system being so vulnerable such as the article describes and a problem in one spot would not potentially cascade throughout the system.
Regretfully the public is not willing to pay what it would cost for the redundancy and security that would be required to make the system less vulnerable.