All this is based on a survey. It would be very interesting to know the number of people that participated in that survey and the tech they’re working on.
If you restrict your employees to browser based office, you would loose a vast amount of productivity.
Their success is probably based on Office alone. AWS does supply extremely fast services and we use it for hosting. But business owners often prefer to use services from a single provider, so MS does indeed have an advantage.
This report also states that Google may be looking to purchase their way to the top of the cloud offering pile. I'm not sure who they would get that would make that much difference; Rackspace?