I have no insider knowledge, but from the outside it sure as heck looks like Microsoft has rebuilt its internal culture since the founding of Google. It certainly doesn’t feel like the MS of Bill Gates or the MS of Steve Ballmer anymore.
If that is true, wouldn’t this imply that the difference between the two isn’t time since these unspecified “trends” began, but instead quality of management?
IIRC MSR was started by Rick Rashid (the inventor of the Mach microkernel that NeXTstep and Mac OS X are based on), and it was always very independent of the rest of Microsoft and its business priorities.
Microsoft was more entrenched and stable.