I have never cleared app data and seldom reboot, neither in Nexus nor Cyanogen, despite beta-testing a lot of stuff. I just asked my wife, she never did these things on Motorola's and Sony's "roms". Are you sure that these events are that popular?
Clearing user or app data is not required when doing OTA updates on Android.
The partitions that get updating are completely separate from user data. This myth keeps spreading for some reason though...
The only time user data gets wiped is when unlocking the bootloader which is a very valid security feature in order to prevent bootkits and data theft. It gives big clear warnings to backup your data before doing so.
Mine Samsung S4 mini reboots by itself once in a few days. Hadn't bothered to catch the reasons. And it surely knows how to hang itself for half a minute when doing large app updates or otherwise IO-heavy operations.
