And yet the internet is hosted primarily on Linux machines...
It would appear they work just fine for global networks. Well, that's only in practice...I'm not sure how it would work in theory though.
I'm talking about a multi-user network on a domain, not the internet where almost everything is accessed from one local account.
I don't quite know how you figure that. Besides what's already been said, the best permissions are the simplest, the ones where it's most difficult to make mistakes. There's a huge problem on Windows of people not understanding the permissions because they're so complicated, whereas Linux permissions make it easy. It's Occam's Razor all over again: simpler is often the most effective. I've never found myself limited.
That's wrong. "The best file system" is totally dependant on the situation. I'm not saying Linux file systems aren't viable solutions for some situations, but I am saying that NTFS is better for a domain with a lot of users (my school district has 800 or so and I can't imagine using anything else. it would be such a pain!)
I think you're confusing 'complexity' with 'versatility.' Trust me, it's not hard to fix permission issues on Windows servers. I've been doing it for the last week. We're restructuring our entire server structure (converting 'building servers' into 'role servers,' which is much more sensible now that all the servers are located in a single location). NTFS (not to mention active directory and all of the other server management tools that come standard with 2003 server) have the features they do for a reason: people use them. They don't add in extra fluff to make things more difficult for admins.
Of course, that's an entirely different argument.