The point is, that not so long ago, it wasn't really necessary to do that with Apple stuff. Advisable perhaps, but rarely necessary.
I lost my first data from a Mac in 1994 when a HD drive died. A back up is, was, and always will be absolutely necessary.
Do you really believe that there was a halcyon day when all apple products worked right out of the box for everyone, everywhere? If you really believe that I've got this bridge in Manhattan I can sell you. Go back to these forums to when iPhoto 6, 7 or 8 were released. Each time there was a chorus of folks who lost data, who thought that iPhoto was getting worse with every iteration and all the other types of posts that you can read here today about iPhoto 9.
I have no problem criticising Apple. I don't think this iPhoto is a particularly compelling upgrade. That said, for me, it was an absolutely flawless processes.
However, criticising Apple here is pointless. If someone comes in with an issue, where does it help to say "It's Apple's Fault". Does it get you one whit closer to solving the issue? Better, I believe, to stress again and again the elements that a User can do to proof his/her set-up. Backing up is the most simple and basic thing that any user can do to protect his/her data. Feeding back to Apple via the Feedback process is something a user can do. Sitting on a bar stool complaining about Apple is a pointless exercise.
It really has to be started very bluntly: any one with valuable data and no up-to-date back up is as wise as any person who motorbikes without a crash helmet or drives without a seatbelt. Neither of these will prevent accidents (and the accidents may be your fault or the other guy's) but they do improve your chances of coming out of unscathed.
To suggest otherwise is foolhardy.
Regards
TD