"Microsoft is synonymous with software that you use on your desktop"
This is insightful. While some of us geeks have a grudge against Microsoft, most people don't. They probably do, however, have a mental separation between the desktop and the web.
Microsoft was slow to embrace the web because it threatens their core products. So the web grew without them. Now they're saying, "oh, we're on the web, too!" But when people think of the web, they don't think of Microsoft. They missed the chance to make that association. And it's hard to get it back.