Actually, the way it is now requires 4 buttons for almost every jump. There’s the ‘w’ key to ensure you don’t jump straight up, the ‘shift’ button for jumping across gaps (there are plenty of these), the ‘spacebar’ for jumping, and the ‘ctrl’ button for jump-crouching.
That means to make it over the plethora of jumping puzzles in Black Mesa (they were in Half-Life, so it’s not the Devs’ faults for including them) one must use the pinky for pressing two buttons, the thumb for pressing one, and the middle finger for one. Or if they are feeling risky then they must be able to quickly move the pinky right at the jump, making sure not to let it slip and press the ‘Windows’ key, and press the crouch button.
Not very comfortable for everyone, especially those who only/mostly use consoles and were actually interested enough in Black Mesa to try the PC.
EDIT: Or they could use their ring-finger for the ‘shift’ key. Again, not the best setup.