So who's surprised?
As per title, who's surprised here? Because I'm bloody not.
There's a reason I grudgingly put up with getting fleeced by HP for genuine cartridges for my small laserjet printer at home, and it's the desire to have a valid warranty. It's the same at work - what's the point in buying an extended warranty on a large printer/MFD if you then use non-branded cartridges that invalidate the warranty? (Yes, I know, you could use unbranded carts and disable cartridge checking - it's still the sort of thing that a service engineer will hide behind as a reason not to fix your hardware).
If government wants to do something about this, they should start by kicking HP et al in the pants over how they tie their hardware warranties to the usage of consumables. Of course, that would force companies selling printers to admit that actually they're in the printer ink/toner market rather than the printer market...