The AAIB and the CAA do actually have a point and they are NOT blamimg the spanner they are criticising the mechanic.
We have seen lots of people with road based GPS being "over reliant "or following it blindly resulting in cars in rivers, trucks where no truck should be and the like.
Airborne GPS is no different. If you follow the magenta line and have no idea where you are or what the surrounding terrain and airspace is like then you are a plonker.