The primary push for up-grading the operating system is the DRM crowd... aka Hollywood.
The number one reason to not upgrade is your CPU and system.
8.1 requires drastically more chip speed -- and is written for 64 bits NOT 32.
Silicon Valley hasn't shipped a 32 bit machine in years.
I must conclude that some provision has been made for emulation of 64 bits -- but -- on the whole -- older machines actually can't use 8.1.
Just as XP can't run on 16 bit machines. Any attempt at emulation causes the machine to slow down to the point of futility.
This transition to 64 bits goes back quite a ways. It's really designed for Hollywood.
32 bits was plenty for all other uses. The old IBM 360 could run an entire Fortune 500 company with 32 bit 'words.' 64 bits was a double-word, 128 bits was a quad-word.
Of course, the cheapo towers being thrown to the curbs these days are fantastically more powerful than an IBM 360 -- which would not be able to drive an iPhone.
