Sadly, the real lesson we need to learn from Battlestar Galactica is not this. They weren't saved by old software, they were saved by not having critical systems on the network unnecessarily.

Our water and power utilities need to re-watch the pilot.

Why are our water and power utilities connected to the internet? Is it so that the employees controlling them can work from home? If so they are accepting too much risk relative to the benefit.

To be fair, it was both. Those ships that got the recent upgrades also got trojans that Caprica Six put in the defense mainframe with Baltar's access codes.