You have users who want Modern Apps, Users who like both, And then users that what nothing with them. Perhaps this could solve the problem:
"Native" Desktop Only
For those "PC Experts" Technical Preview is
ignoring targeting. Disable the Windows App subsystem completely, Only native applications can execute. Windows Apps are uninstalled, Store is disabled. No
PhoneHome Microsoft Accounts required. Hides nothing from the user, Options aplenty. The User tells Windows what to do, Not the other way around. Great for Businesses and Power users.
No restrictions, User is allowed to trash and destroy the system if they so desire to do so.
Just like "Native Only", but has the Windows App Subsystem and Store enabled. Prefer to use native applications rather than Windows Apps (for say Use classic calculator instead of the modern one and Control Panel Instead of
PC Settings). Doesn't hide as much from the user, and is configurable. For those who grew up with the Windows Desktop or Developers needing access to the Windows App subsystem.
Currently what windows 8.1 offers (I think). No preference to either type of executable, user sets launch choice. Attempts to hide options and system internals from the user. Windows tries to keep user contained their account directory, Strongly discouraging access elsewhere. Choices are limited (For Example Windows Update modes: "Automatic and then Automatic".
Metro Only/"Bob" Mode
User mode native applications are hidden to the user, Only Windows Apps can be used (Think Windows RT). Options and choices are limited to prevent confusion or spontaneous combustion due to brain overheating. For those who don't know the difference between a Application and App.