]Some of us KNOW that Unix based systems simply DO NOT NEED to reboot to install new software or hardware drivers or pretty much anything. There's a way to remove and reinstall everything without the downright ANNOYING need to reboot
This is untrue. Interestingly, the mach kernel design actually does allow this in most cases, but it ended up being too slow, so a moderately large number of drivers are in-kernel now. Doesn't apply to a Safari/WebKit update, since that's a higher level framework, but it does apply to some of the other updates.
Theoretically for this one they could have done a "please relaunch all apps that use webkit now" of course. It'd be difficult to make automatic though, and most people have no idea which apps use WebKit.
As an aside, "unix based" is a silly phrase. I sorta wish Apple would stop using it. "A weird mixture of mach, freebsd, netbsd, openbsd, some gnu stuff, and a lot of apple stuff" is a lot more accurate, although it doesn't really roll off the tongue.
And despite what some people seem to think, Safari is *NOT* part of the Apple operating system
This is untrue as well (see /Library/Frameworks/WebKit.framework, and check the modification date). The bulk of Safari's functionality is in WebKit, and WebKit is updated with every Safari update. Just in case... before you try to tell me I don't know what I'm talking about here, please check for my name in file:///Applications/Safari.app/Contents/Resources/Acknowledgments.html .
<edit> heh, I assumed my name was in my profile here... guess not. I'm the David Smith in the webkit contributors list in that file </edit>