As more nation-state actors get into the hacking game, businesses and governments become more interested in which industries are the most vulnerable. To answer that question, you have to ask which are inherently the most vulnerable, which are the most desirable for hackers, and where do the two meet?
A lot of hacking is devoted to making money, communicating a message, or just making a mess. Cyberwarfare, however, has only ever really happened if you count the Stuxnet attack on Iran’s nuclear program, which actually succeeded in creating physical damage. But it seems safe to say nation-states—your own and others, both friendly and not—are going to be as interested in cyberwarfare as they are in cyber-espionage.