Sounds like you're saying they wanted a reason to write a new file-system that made SQL Server more efficient. But doing that would piss off the rest of the software industry, and would (correctly) be seen as leveraging their OS monopoly to extend an advantage into the database sector, in which they have real competition. So they instead put forth the explanation that they were trying to help people keep track of content on their huge new disks, knowing from the start that there was no way it could ever work for that.
Was that what you were getting at, or did I just make up my own conspiracy theory?