Hi Leo, hardened mode indeed may prevent you from using some apps (downloaded from the internet, not signed by a code signing certificate with a low number of users using the same app) - but isn't this exactly a category of apps that inexperienced users should not be using? If you know what you are doing, what is the source of the app, and why it is not signed, then you are qualified as an experienced computer user and might be happier with the Hardened mode switched off.
To sum up, I would argue that the Hardened mode is indeed more suitable for less experienced users.