Personal Happiness at all cost = selfishness
Activism at all cost = selfishness
Personal contentment (which leads to happiness) is valued and important. However if that is done at the expense of innocents such as the children mentioned in your story, then that particular pursuit of happiness is selfish and will eventually work against one's own happiness. Kind of a Karma thing.
Activism overly pursued without thought of consequence or emotional damage to innocents is also selfish and will work cross purposes to the intent.
In my opinion, personal contentment is directly proportionate to how caring for others (or at least the desire to) is manifest. I do believe that my being happy and successful is the best argumentation to the JW's. I have returned to the vomit yet I am happy. This may cause and has caused the JW mind to struggle with the disconnect. Not a JW yet still happy.
I do what I can to support people in their decision making process. That has included being a friend to someone while they were df'ed and working towards reinstatement. I knew full well the relationship would end once they went back, but that person needed some social connection while being cut off. I believe it is just one more person who has to honestly admit there are good people in this world that aren't JW's. I hope eventually that seed will germinate but if not, I am happy that I provided support. Her going back, didn't rob me of the joy.
Activism can be a great catharsis for dealing with the initial anger felt after a great loss (eg MADD) but you'll find more is needed in order to find your center (grounding) and work towards creating a life after the loss wherein you can build that contentment and happiness.
