Edited for brevity, and yet the words continue to outline the truth.
I speak for myself only, but simply put... there is no "fear of repercussion", there is no "shyness or fear" of anyone's pro or con reaction, there isn't even any deeper psychological debate to be had other than my singular choice.
I have pics, I simply choose not to share - until I choose to share.
And having met a couple of people from here, it can be validated that I really have no fear about meeting someone face to face.
Thus, maybe the question becomes "what is there to be gained from showing one's pic, that others could not glean from taking the time to know you better as a person?"
Just a random thought, topical or no...