Why Not Microsoft?

1. Microsoft competes using business and personal tactics, not on technical merit. (Using SCO to run an anti-Linux malicious legal witchhunt designed to spread FUD about the legality of Linux, scaring away corporate customers of Linux; threatening PC manufacturers who offer Linux; using lobbying money instead of technical arguments to push OpenXML through)
2. Microsoft doesn't try to create better products than competitors; it tries to make competitor's products worse. (Java is an example where Microsoft was foiled.) As a result, thousands of innovations never see the light of day unless Microsoft can make more money out of them.
3. Microsoft has a culture of reliance on deception rather than openness. (In its earlier days, it tried to cover up security flaws rather than fix them numerous times. Currently, its claims about OpenXML being an open standard are disingenuous: Microsoft uses various techniques to make it almost impossible for 3rd parties to write software compatible with Microsoft Office even if OpenXML is followed.)
4. Microsoft decisions are technically flawed. Microsoft sets off to make radical changes in the way things are done, relative to Unix. Several years later, it then begins a costly process of converting its legacy of bad code into practices similar to those of Unix. (Example: DOS's lack of memory protection, user accounts, application settings instead of the registry, home directories, making security a priority, remote access)
5. Microsoft's "copy, don't innovate" strategy has a significant opportunity cost for customers who don't get useful features for years after they are available elsewhere. The problem is compounded by Microsoft's monopoly. (Example: tabbed browsing, available for 4 years on Opera and 2 years on Firefox before Microsoft could make it available on IE.)
6. With Microsoft, customers have no chance at code ownership. So features Microsoft wants to add are added when Microsoft wants them. A customer can pay to have features added to an open source app. Not so with Microsoft products; customers are entirely at Microsoft's mercy. The problem is exacerbated if this refers to a feature that is useful to a small minority of customers, or just to one customer.
7. Developers with smart ideas can add features to open source software. Not so with Microsoft software. Such ideas cannot be widely distributed without the entire piece of software being rewritten as an alternative, or Microsoft deciding to support the modification. No such ideas are ever part of Microsoft software. Thus, Microsoft stifles creativity (unintentionally, in this case).