secuirty
"I didn't know I installed Safari on this computer, but if I did I guess I should update it."
this is the real issue here
how do you know that what looks like the Apple updater (or even the Firefox updater) isn't some new piece of malware that's slipped past your virus checker?
and even though it occurs to you that you don't remember installing Safari, you click the update button anyway
if it had been malware, you've just given it permission to install anything
i think the Mozilla dude brings up a very good point
we are TOO trusting of our updaters and really, thanks should be given to Apple for showing us this.
blindly clicking update is as bad as blindly clicking a link in an email