Google Nexus 7 Tablet (2012) The reason of why must of us arent getting KK 4.4 OTA yet

[Jc18able]

This should explain it:

[Developer Changelog] KRT16O To KRT16S, Critical Bug In Full-Disk Encryption Explains Hotfix

However, there is one emergency fix for a serious bug that could result in the loss of access to encrypted disks on a device upgrading from 4.3 to 4.4.