You know, that's interesting. Titanium Backup insists that my external SD card is not writeable, there was no way around it. I had to back up to the internal sd card, and manually copy the backup directory out to my external SD card. Since I only keep one backup for each app, it isn't a real problem (less than a GB.), but I do want backups on removable media.
I find it hard to believe that Titanium Backup hasn't been changed to work with 4.4.2 by now, but that would explain what I saw. I even tried uninstalling TB and re-installing it from the Play Store, but no luck at all. That would explain what I saw with TB, but that is bizarre, since they tend to be on top of what's happening. Maybe not this time, though. There may be less people rooting with 4.4.2 due to the Knox problems, I don't know.
Weird.
And yes, I can verify that if you try to go back to 4.3 from 4.4.2, you'll brick your phone, so that's not the right answer *smile*.