[rmateu]

Probably the best informed reason:

>Streamlining the operating system.

>Since it contains only the kernel, device drivers, and configuration files — and absolutely no user data — the iOS 10 kernel cache can be left unencrypted without any concerns over security or privacy.

[Here's why the iOS 10 kernel cache is unencrypted | iMore](http://www.imore.com/heres-why-ios-10-kernel-cache-unencrypt...)

[mikeash]

That would seem to imply that previous iOS versions put user data in the kernel cache. Why would that be?

[oddevan]

Alternatively, they just decided to encrypt everything, maybe in case there was some sort of user data in the kernel cache. Now that they have a better idea of things, they can be selective.