... First, I am not sure that email is really by Gates -- from reading his writing or listening to him in the past, it really does not sound like his style. Also, "I reboot my computer ... why should I have to reboot my computer?" I find it hard to realize that he wouldn't know the technical difficulties in replacing a dll while the system is running, and possible ways around this, and the current state of affairs. However, maybe I'm giving too much credit here...
Maybe what he ment by 'why should i have to reboot my computer' is 'why does the stupid thing practically *force* me to reboot *now*'? It's something that really bothers me in Windows, you know, the 'would you like to reboot now or be reminded in 5 minutes?'. Usually, I don't want to reboot at all at that time, but i have to because the stupid window keeps popping up every 5 mins.
When linux updates, it tells me that a reboot is needed to complete the update and then leaves me alone. Much better.