I don't like allowing the use of keyboard and mouse for console games, they should keep the playing platform leveled and not give any advantage to those who prefer a mouse/kb. If you want to play with a mouse and keyboard, stick to playing on your PC.
Well that makes no sense.
Considering a USB mouse and keyboard are cheaper than a new controller (with rebates, I have seen many free keyboards & mice).
And keyboards offers a more versatile way of communicating with the console, specially when using a internet browser.
So I would have to suspect, that better than 80% of the people will try with a keyboard.
Some people play better with a keyboard, others do not (like me).
I am much quicker with a handheld controller with jumping, most movements, changing weapons, etc.. than I am with my wireless keyboard & mouse (other than looking left to right).
Granted, I game very rarely nowadays.