I have this proble since JB till now latest KK on Nexus 7-13. Sometimes (or even often) rotate stops to work. Reflashing firmware or factory reset in the meanwhile (for other reason btw) did not solve. Can be short or days of not working rotation. Reboot worked a few times but often not. When rotation works it works good, so it is most ptobably a firmware issue.
When not working I use a 3rd party rotation app. Needed anyway for forcing reverse portrait on all apps when using tablet while charging battery and have charge-cable more convenient upside down on top of device.
Verstuurd vanaf mijn Nexus 7 (2013), iPad Mini Retina of Moto G Lte