The consensus was that it depends on your framerate if it works or not. If you lock the game to 30 fps, holding down Q works properly. If you lock the game to 60 fps, holding down Q does not work properly.This is a weird one, but I can confirm that it does work on some systems. I've had no issue using either M+K or a controller. It may be a ghosting issue with certain keyboards. Have you tried pressing only the "Q" button, ensuring no other buttons are depressed at the same time?
Since it seems that some people have success fiddling with timing settings, try switching the game to Fullscreen mode if you're running Windowed/Borderless -- grant as much exclusive access to the game as possible.
You cannot really ask people to run at 30 fps, when 60 fps looks so much smoother...
This is definitely not a ghosting issue, or related to the keyboard you use. I have tried holding down Q with no other buttons pressed, it doesn't work. I have tried using a different keyboard, it doesn't work. Also, why would the problem go away by editing a config file if it was the keyboard which was to blame? That doesn't make any sense. I ask you, are you really being serious with these suggestions?