The point is not whether CCW permit holders run to the defense of others in a situation, the point is that they be able to protect themselves in such a circumstance. If there are enough CCW holders around, then the potential for mass murder, ala Virginia Tech, is greatly reduced.
Further, any CCW holder who has as their objective, any goal other than to protect themselves or their immediate family, is sadly mistaken. There is no obligation to act in defense of others. In fact, in most states, a CCW holder is prohibited from acting in defense of others. The fact that there are legal defenses if a CCW holder does act in defense of others, does not change the law.
Again, if there are enough CCW holders, able and ready to defend themselves carrying in enough places, the opportunity for mass murder is greatly reduced.
Finally, a CCW that does not require at least a minimal performance standard with a live weapon may put the holder at risk if they do act. If your state does not require weapons proficiency as part of the licensing, you would be well advised to attend a recognized self-defense class. This will give you at least a very basic understanding, and provide an affirmative defense in the event of an incident.
If you genuinely want to protect others, become a LEO; otherwise, learn to protect you and yours only.