Preventing breaches is an objective, but it's purely secondary to CYA. This is why the Security Strategy Policy exists and often looks so out of touch with reality:
1. An external consulting firm advised on that policy document.
2. Someone signed off on that policy document (CEO/CTO/COO/etc).
3. Everyone below that person ticked-off every single clause in that document.
4. Breach occurs.
5. Employees can't be blamed, they did everything that was asked of them
6. CEO/CTO/sign-off person cannot be blamed: they sought, paid-for, received and heeded professional advice.
7. The external firm cannot be blamed, as their advice is "in line with modern security guidelines."
In this sense, no one should be shifting focus from whatever the policy document says because then they can be blamed.