Yes but no. IoT is about telemetry, not control. You can instrument the fuck out of the world and it lets you know it, not control it. Just because my smoke alarm can be controlled with an app doesn't mean I can set my house on fire with it. Yes, there are servos in the world connected to the Internet. Yes, a lot of them lack the security they should have. But no, it's not a logical progression from there to "The next president will probably be forced to deal with a large-scale internet disaster that kills multiple people."
Again, I disagree. There's this leap of faith that the more things are connected to the Internet, the more damage can be done... but the things that can do damage could have been connected to the internet a long time ago and they don't. It's stupid that Chrysler's control system allowed disabling the vacuum assist on the brakes. But it didn't disable the brakes. Theoretically, a hacker could kill the regenerative braking on your Prius. But they couldn't kill the brakes on your Prius. And it's great that Schnier is raising the hue and cry about this stuff because the first big dumb things that are going to be automated are semis and hell to the yes you can cause a shitton of damage with a rogue semi. But the hue and cry should be "we should worry about this stuff" instead of "ZOMG we need to worry about EVERYTHING" which is what these articles tend to be.