Oh my. I was afraid of starting this thread myself because no matter how you put it, such a thread on these forums would smell too much of a troll. Anyway, now that the thread is here I might just as well answer.
You say that most hardware and software is designed for windows, and that's indeed a good thing. However, there is a reason to this other than windows merely being so popular. Windows is a good platform. The fact that so much software is made for windows is because so many developers use windows. There are many reasons for developers choosing the platform, but technical issues are among them. The ease of doing things, everything the platform provides, and the mechanisms it offers.
Some of the strong points are Asynchronous I/O design for server apps, DirectX for multimedia abstraction, audio compression manager, COM objects and how they can be used by third parties, heck even the Clipboard. Lately, the .NET is becoming another strong point, but that's more interesting one because it's only loosely tied to windows. Anyone is free to implement the whole system which is standardized and documented. Since windows is providing so many standard apis, application development is straightforward and sane.
Windows also has a strong UI system, and mechanisms to seamlessly integrate and interoperate with it. Clipboard, Drag&Drop, Common Controls, the whole window class mechanism for widget management, etc. On *nix platforms, the X11 natively only supports bitmaps and primitives, no widgets whatsoever. As a result, all applications use whatever libraries they want to, and results tend to look different based on what libraries were used.
Since the *nix systems doesn't provide common apis for many important highlevel operations, they tend to end up with multiple different libraries implementing the same things, in different ways, at different levels of conformance to standards. For example, see all the XML libraries out there. For windows, there's MSXML and anyone's free to use it. Ofcourse, nobody's forced to use it, but if someone got the idea of selling an xml library I'm sure we'd have another fight about integration and competition killing practices.
Having all the apis available is what makes the platform nice for developers. See PHP for an example. PHP was already damned popular even before anyone had bothered to write any kind of language specification. All development was rather empirical, with "let's see if this works now" attitude. Yet, developers loved it, because things were so easy and straightforward. With all the libraries bound to the language, everyone could use all those things without hassle. Having to install libraries and especially having to deal with redistributing libraries to users of the software is quite quite troublesome. PHP is widely trusted because when the server supports PHP, you know your applications should work there unless they depend on something unusual. Same applies for windows. When you have a windows system, you know your applications are going to work. With a linux as an application platform, you only have the kernel and whatever libraries the language guarantees to exist. Anything else and the users have to install something new, which is a hassle.
Phew, that was a long post and only addressed some specific things. There are multitude of reasons why windows is such a great OS, and a lot of them have to do with specific tasks at hand. For a generic view, it's tough to point out things because there are always exception cases where another system is better, and people tend to think that finding such exceptions invalidate everything the generic points stand for.
Feel free to ask more specific questions for more specific answers.
