Underperformance of Rapid Fire

Explain why it's an issue
The skill does not have a wide use because of:
1) The skill is related to Path of the Scout which is not usually invested with enough skill points therefore it leads to low damage potential
2) The skill requires stationarity which is not welcome in most cases on the battlefield
3) Overall dps of the skill is not high enough to compete with any other primary skills (e.g. Spiral-Fletched Arrow) supported with auto attacks.
Propose a viable solution to the problem:
Rapid Fire will reduce run speed of the enemy by 25-40% (can be tweaked). This effect will apply only during the channeling.
It may justify required stationarity and slightly increase the popularity of the skill.