Default [Q] /system mount rw on kitkat?

I have a rooted stock kitkat nexus 4. I've been trying to use various sql editors to edit some values and it always fails, despite getting the popup that root has been enabled for the application.

It looks like the problem is /system is mounted ro and never manages to get remounted rw.

I tried running an app that does nothing but remount /system, which gets the same success popup but also does not change the mount to rw.

If I adb to shell, I get a non-root shell and "su" just hangs.

All the apps that want su access say they have succeeded in getting it. Ideas?