Businesses don't work like that
"The desktop has been dead for some years, resurrected to an afterlife of video editing and CAD."
That's quite simply not true. Look at most businesses, educational establishments and government and you'll see desktops, and the purchase of them continues. There's no reason for a callcentre to give laptops or other mobile devices to its telephone agents, whilst there's every reason not to. What about staff whose job it is to be office based and process documents? A fixed desktop is by far the most cost-effective and efficient way to have these staff complete their work. Whilst schools continue to move to mobile devices for staff and students, there are tasks far better suited to desktops. Equally there are schools where mobile devices aren't an option (cost, damage, theft, forgetfulness), so robust and secured desktops are put in place.
The author needs to think about users outside of the IT sphere, of users who don't have the knowledge or desire to use mobile, and of companies and establishments who have no need to change to mobile devices.