Quite possibly, this is the cruelest thing that you could do to someone. Particularly when you don't understand it or only know part of the truth (at best), anyway. Let people live; let people learn. (Those are not my words but well said.
If a person wants to be a part of your life, they will make an obvious effort to do so. Think twice before reserving a space in your heart for people who do not make an effort to stay. Must remember this!
Not everyone thinks the way you think, know the things you know, believe the things you believe, nor acts the way you should act. Remember this and you will go a long way in getting along with people - Arthur Forman