He has a point about precision because the human body is capable of acceleration itself when it comes to mouse movement. I want to be able to click accurately and consistently without error so why introduce more factors that get in the way?
It is more important to have stability in movement and how a user sees it.
Mark Cranness made this fix for old games which force ... If you don't play old games which enforce mouse acceleration, then you don't need this.
This is not entirely correct. Goldsrc and Source being prominent reversals of this role. (With Windows 7)
EPP has not entirely disappeared so this fix is relevant as enough popular new games use it.