- Windows 10 has a more restrictive license. Telemetry sharing and automatic updates cannot be turned off on all Win 10 upgrades.
- The shrinking and eventual elimination of Windows 7 devices means fewer older devices to support, fewer patches to backport, etc.
- People that have paid for their Windows 7 license offer no further revenue to Microsoft. Microsoft is basically losing money on them, being obliged to continue supporting a device that paid for its license five years ago. People on Windows 10, however, provide "value" (as a stand-in for direct revenue) to Microsoft in the form of analytics and telemetry.
- People on Windows 10 are inherently more likely to participate in Microsoft's other, more profitable subscription-based models ala Office 365.