Nokia N95 - always good for a joke

why does the phone to refuse doing an update of the phone software when there's no sim card in?
What if I have to be reachable and need to use the sim in another phone?

Apart from being totally broken, and not usable anymore, after only 9 months (my usual turnaround time for mobile phones gets near to the two years, if not even longer) - now I can't even delete my private data with a phone software update(I didn't find another way, there's no "delete all user's data" button) without inserting a SIM.