The author seems to ignore the main case for conversational interfaces - which is not to replace the software, but the software user.
Not telling your car to turn left or right, but telling your cab driver you're going to the airport.
This is our usecase at our startup[1] - we want to enable tiny SMBs who didn't have the budget to hire a "video guy", to get an experience similar to having one. And that's why we're switching to a conversational UX (because those users would normally communicate with the "video guy" or girl by sending them a Whatsapp message, not by clicking buttons on the video software)