Hello all, first post but I've been lurking for a while.
Users like those that participate in forums like these or read tech blogs and even the tech blog writers themselves are only a small percentage of Windows users in the grand scheme of things. Microsoft collects Windows usage information from the Customer Experience program on all their products, the default is checked to yes and common users tend to keep default settings. Based on these usage statistics common users make up over 80% of the install base while users like you and I are under 5%. The information has shown that most common users don't use the start menu, they mostly launch apps from shortcuts on their desktop or even use explorer. Working in IT I can say that a majority of our users fall into the same usage patterns, their desktops are littered with shortcuts. The other thing is that a majority of consumers PC functions involves browsing the internet, social sites, email etc and when required work on that occasional word document. What has been happening is that people are buying iPads, or other tablets, for their daily content ingestion then fall back onto their PCs or Macs when they need to do "other" work. The point I'm making here is that we need to take the blinders off in thinking that everyone is like us or use computers the way we do because we are in the minority.
Booting into the Desktop or Metro? Most peoples view of this is based on not only what they are used to but the fact that all their current applications are desktop apps. The common user is going to start their collection of Apps and they will out number their desktop Apps rather quickly. If their Windows 8 booted directly into the desktop they would be saying why doesn't it just boot to Metro so they can get to their Apps quickly.
The Enterprise. Most companies don't adopt early into a new OS and as in past iterations of Windows the consumer will have used the latest at home prior to even using it at work. Once the Enterprise is ready to start their upgrade cycle to Windows 8 most employees will have been using Windows 8 at home for some time already. Microsoft has never targeted Windows 8 for the Enterprise anyway, actually they have even said themselves that they don't expect adoption at the Enterprise level yet and that Windows 8 use will be more like the iPad as a companion device. All the Enterprise talk comes from tech blogs and the media. If Windows Server 2012 is any indication of what the Enterprise version of Windows 8 will be then it may boot to desktop after all. BTW, Windows Server 2012 still has a Start Screen.
Lastly, the Windows 8 Blogs are a good source of information on the why's of Windows 8 & Metro. They go into much detail about their design choices and is always a good read. From a lot of the responses and opinions I see in forums and tech blogs on Windows 8 I don't think many "techies" actually read it. Building Windows 8 - Site Home - MSDN Blogs