Smaller shops like ours, can't afford to get huge backup capacity to backup the servers and *everything* on each client machine. So in a small shop scenario like this, backup is on priority basis only.
If you have 150 gigs of backup space only, and you can't buy anymore (executive decision/budgeting, etc.) -- what do you do?
A) Back up your critical company maintaining servers and the databases that take up 100+ gigs on their own, which leaves you with +/- 50 gigs right? Oh darn...those executive and manager computers have files on them of "high importance" and then the QA system down the hall has our client report and inspection pictures on it from all over the country -- there's another 40 gigs combined.
or
B) Screw everything just so you can have space to backup everything on each of 100 client machines you have, with an average HDD size of 20 gigs, of which from that 10 gigs is what the user deems as "precious" files. (emails/documents/jokes/pictures, etc.).
Now in our office each user has a network drive that we give them a small slice of space, all net drives are in the backup schedule each night.
But there still is no way for us to backup EVERYTHING. Hence, the scenario originally presented is feasible to occur without the user's particular folder being included in the backup. (Even though the thread author did state they do in fact have backups after all).
So while "um..restore from the backup ..duh" sounds like common sense....believe it or not in some shops that don't have Bill Gates size budgets, we have to be very selective and "choosey" of what we back up.