How does Apple manage updates at the same time for ALL

and what's stopping MS, NOKIA from doing that...

I am super frustrated with MS, NOKIA and AT&T for not getting the update on My Lumia 920 bought on day One. If only Apple had a bigger iPhone (Can't go back to that sad tiny screen), I would have jumped ship today out of frustration.

I love my Lumia but their collectively inability to not deliver updates on time or (collective ability to screw early adopters) makes me sad. I know there are many others like me who just hate that MS, Nokia can't provide us update experience similar to Apple. Kudos to Apple for figuring it out and doing it right way.