As we stated, it is happening more often if a user reboots in between the default weekly schedule. If they do not reboot, it "should" retain the optimization history and skip it.
So at default settings, maximum 4 times a month it would be performed.
If someone changes it to daily maintenance...
I think we still are :)
Seriously, though, we thought the same thing until we did the tests ourselves. When launched from the automatic maintenance screen, we saw it defrag our C:\ SSD drive, perform around 8 phases of consolidation (which I believe is part of the defrag process in Windows)...