And with the way people are so used to instant communication, the shock of the removal of electricity (if it was a nuclear attack, most likely powerstations would be targets) would just make everyone go apesh*t.
The winter in New England was particularly harsh this year, with several weeks back in January falling well below 0 degrees F. At minus -10 F it's fairly hard to keep a home heated even with the electricity on, and exposure to those temperatures for long can be deadly. During the depth of that freeze, I was remembering the NorthEast Blackout which occurred only six months earlier (which took out the entire North East United States, except for New England), and was thinking how lucky we were that the blackout happened during the summer, when electricity is a mere convenience, rather than the a fundamental source of survival during harsh winters.
If a similar blackout had occurred during those incredibly cold January weeks, I'm not sure how many people would have survived. Shelters (those with generators) would have been overwhelmed, and families with fireplace might have had to host dozens of neighbors for days.
Our society is remarkably dependent on existing technical systems. We were lucky this time that the blackout happened in a "convenient" season. But it should serve as a warning. I hope others besides myself have noticed.