I understand where you are coming from..kinda...but it makes no sense.
You are more or less giving the individual power to make reason of spamming. Regardless of point, it would still be spam if it has nothing worth value to it.
The easiest way to solve this(which has already been discussed around here) is to nerf the amount of points for writing on walls or leaving comments. That then should help, since people will not feel so inclined to do them just for points.
