If you think this behavior isn't already standard practice... you're living under a rock.
This has become the bread and butter of digital age capitalism: Sell a fancy device. Include digital green bouncer on board. Make the device stop working (or cut off features) using the digital green bouncer if payment stops.
Why do work when you can just keep charging for the work you already did?
Personally - it's WAY too fucking late for mere obscurity to stop this. It's time for "Fucking nuke it from orbit with regulation" type approaches. Or, more likely and also much sadder - feudalism.
My bet is that feudalism is going to come back in a major, major way. But your lord is going to hand out keys to digital devices instead of titles to land.
My hope is that we manage to enforce legislation requiring manufacturers to provide all keys to a device. In the same way that it's not legal to sell a home and refuse to provide the keys.