You do have full access to what you buy. While it would be nice to both have full access AND the security, that’s still not denying you full access.

This is not for you, rather for the kind of people that get Ask Jeeves installed when clicking on popups while browsing the Web.

They shouldn't have the same rights? Just because someone is less technologically aware today, you think it's OK to start stripping away their rights? That's like saying poor people shouldn't be allowed to own a house because they won't be able to afford the maintenance.

Many insurances don't cover house repairs if not done by companies specialised on the repair domain....

The more accurate version of your analogy is that they can choose to do their maintenance, they just won’t be covered by insurance (their own or that of a tradesman) if something goes wrong.

That is actually how it is in reality, and maps very well to as analogies go to GM the two levels of SIP.

The new cryptex mechanism could be used to allow persistent modifications to the SSV (that's how it's done on the iOS Security Research Devices), but no idea if Apple will actually implement that.