The difference here is that Microsoft sell a completed version of Windows which is installed on a device. Google create a version of Android which is then modified by the OEM before being installed. Google have no control over these modifications therefore cannot release a 'fix' that will work on all devices.
Google have made attempts to address this and supply a lot of updates via the Google Play Services. It is, however, an issue that will continue to plague Android unless a better solution is found.