Why Microsoft won't extend the Windows 10 free upgrade offer

Microsoft today said it would, as it indicated last year, end the free Windows 10 upgrade offer on July 29.
Today's reiteration shouldn't have come as a surprise: Windows 10 growth, largely spurred by the free upgrade, has slowed since September 2015 and probably has reached a point of diminishing returns.
In September, Windows 10's global user share as measured by metrics vendor Net Applications, grew 28% over the month prior. Since then, 10's month-over-month growth has slowed, first to 21% f