You've asked a very good question. Much about health care is geared toward preventing problems from occurring. The first step in prevention is recognizing what puts us at risk for a problem. There aren't any studies to show the effect of long versus short necks on neck pain. But a recent study from Australia reports loss of neck motion may be a signal of future problems.
They found people with limited neck motion are more likely to have neck pain and/or stiffness. If detecting loss of motion early can restore mobility, then maybe neck problems can be avoided. Check your posture and range of motion. Check to see if you have limited motion in any direction.
If there is a loss of motion, consider seeing a physical therapist for an exercise program to improve your posture, restore your full motion, and build your strength. All three variables may be important in preventing future episodes of neck pain.