As far as friends, I have been on the receiving end of the "cold shoulder", I am not sure if it would be better to hear the reason why. On the other hand, I have done it as well. We had a friend we stopped seeing as she has a large, obnoxious dog who has to be the center of attention during the whole visit. DH is NOT a dog person. Hints did not work.
With family it hurts much, much, more. DH's oldest daughter went through a divorce 20+ years ago and stopped answering phone calls and letters. We tried to give her some space. Found out through another relative she had remarried and had a second kid. I can not tell you how much that hurts. We tried to re-establish contact with her and got what DH calls "the hate letter", detailing all the ways he was a bad father (basically he got remarried and had 2 more kids) and ending with "you were never there for me". When she ALWAYS knew where to find us and SHE is the one who disappeared. So DH has a GD he has not seen for 15 years and a GS he has never seen.
Family, you gotta love em.