Knox is the security mechanism required to support enterprise use, a particular sore spot where Android has been lacking.
You may recall constantly hearing about the use of BlackBerry devices by US government officials - because the BlackBerry was designed for enterprise use.
Knox was tested and certified for use by the US government, all the way up to the Pentagon approving it for Department of Defense use.
http://threatpost.com/samsungs-secure-version-of-android-gets-dod-blessing/100222
It's not going away and there definitely won't be laws passed against it.
Enterprise use is the final smartphone frontier for Android.
Knox or a future equivalent is required to get there.