[samus]

Microsoft had no real competition back then, and in their core business (desktop and office) is still quite uncontested. Alternatives to parts of the Windows, MS Office, and various corporate systems exist, but nobody offers the complete package. Extensions to their platform were never required to be perfect, just good enough that being ubiquitous (thanks to the platform) is enough to sell it.

Also, is it really against the interest of their employer to create products that lock in customers and make it harder to migrate away? Creating a market for support and customization, with MS sitting at the source of the knowledge and being able to sell crumbs by printing books and other training materials, and offering training and certification courses?