[Q] Motorola X Features Flashable zip. topic

We know that installing a Custom ROM loses the unique features the Moto X has to offer like Active Display, Always Listening, Twist to Camera but why can't they be restored or implemented in other ROMS?
I have gotten the APKs and odex of those apps, and am tempted to install a custom ROM without these features and simply push them back to /system. Sounds to easy to actually work.
Why isn't there a flashable zip out there?