"Ubuntu Core" is a similar product [1]
As I understand it, the main customers for this sort of thing are companies making Tivo-style products - where they want to use Linux in their product, but they want to lock it down so it can't be modified by the device owner.
This can be pretty profitable; once your customers have rolled out a fleet of hardware locked down to only run kernels you've signed.
Not if the end user is an operator of safety critical equipment, such as rail or pro audio or any of a number of industries where stability and reproducibility is essential to the product.
Ever seen a default ubuntu splash screen/wallpaper on a train, coffee machine, airport terminal kiosk, bus, or other big piece of slow moving, appliance-y thing?
That is why Ubuntu Core (and similar) exist. More secure, better update strategy, lower net cost. I don't agree with the licensing or pricing model, but there are perfectly good technical reasons to use it.
That's because it is a net negative to the end user and to society at large.
If the end users do not want the net negative, maybe they should pay for the security features instead of expecting everything for free.
This sounds like a net negative for the end user