A. What I have works and has never gotten a virus.

B. My printer won't work with 11

C. My graphics program ($400+) won't work.

D. All those files and tweaks would have to be transferred.  Some probably won't work.

E. My Microsoft Office is missing all the CD's that I used to install so most likely have to buy new.

F.  My monitor won't work with the new computers.

G. They dropped WordPad which I use extensively.

H. My browser with it's tweaks will be lost as some stuff won't work.

J. My television card probably won't work.

K. Want to add, most new computers have no CD/DVD and no provision to put one in, I still use CD's and DVD's for a multitude of things, including music for my older vehicles.

So I end up spending a bunch of money, lose a bunch of stuff, gain nothing but a little speed.  And that speed is offset by the fact that Microsoft will constantly update 11 and break stuff that worked before the update.  And those updates take time away from using the computer.