From the bloatware link:
For example, with reference to the most recent version, Windows Vista, Microsoft engineer Eric Traut commented that "A lot of people think of Windows as this large, bloated operating system, and that's maybe a fair characterization, I have to admit." He went on to say that, "at its core, the kernel, and the components that make up the very core of the operating system, is actually pretty streamlined.".
WHY not just give users the streamlined fucking version in the first place??? It's all about a) money and b) control over what users can and can't do on the computer... deals with record and software companies? This is one reason why there is so much "hate" for MS.