I expect my devices to uphold the security model they advertise.
My desktop OS (macOS, for what it matters) doesn't ask me to approve permissions for apps, so I assume that anything I install has whatever privileges I have (or root privileges, given the broken must-install-as-root behaviour of many of them).
On the other hand, for example, Firefox asks my permission before allowing sites to use the microphone or camera, and I expect it to enforce that. If sites can get access to my microphone or camera without my giving them permission, then Firefox has failed, even if those sites have got that access through unexpected means.
I agree it's very hard to have a secure but useable general-purpose system—but pretending that you're offering such a system while not actually having the appropriate mechanisms to enforce it is, arguably, an even worse solution than offering an utterly locked-down system.