The problem is that it's downstream backports and hardware enablement - you're running an old forked artisinal kernel maintained by Canonical, you will only get

The problem is that it's downstream backports and hardware enablement - you're running an old forked artisinal kernel maintained by Canonical, you will only get bugfixes if known to be severe enough to be flagged, and all this patching deviates it from mainline and can itself introduce new security vulnerabilities not present in mainline. This differs from an actual later release which is closer to mainline and includes all newer fixes, including ones that are important but weren't flagged, and with less risk of having new downstream bugs. If you're going to fight pedantism by being pedantic, better be the right kind of pedantic. ;)