Comment by chithanh

I put the blame squarely on Microsoft, how they released a turd with WP7 (a shiny one with responsive UI, but nonetheless a turd).

About phone OS upgrades, remember the HTC HD2 which originally released with WM6.5 but could be upgraded to WP7 and then to WP8 through after-market community ROMs. It was also Microsoft's decision to not officially allow that.