While it may be "by design," then the package system or something else is broken "by design."
On a system that uses signed kernels, the unsigned versions of the same kernels are also installed alongside. When I upgraded from 16.04 to 18.04, Grub choked because it found the unsigned kernels (which I wasn't even using).
Possibly the process behind installing signed kernels should be investigated? Currently, when you install the signed version via apt, this has a dependency on the unsigned version, both are installed simultaneously, and that doesn't seem like it should be the case.
While it may be "by design," then the package system or something else is broken "by design."
On a system that uses signed kernels, the unsigned versions of the same kernels are also installed alongside. When I upgraded from 16.04 to 18.04, Grub choked because it found the unsigned kernels (which I wasn't even using).
Possibly the process behind installing signed kernels should be investigated? Currently, when you install the signed version via apt, this has a dependency on the unsigned version, both are installed simultaneously, and that doesn't seem like it should be the case.