An OTD person has reasons why they left, reasons which may not make sense to a person who never had the urge to leave we each have our own experience in this life that is shaped by those around us, a person who had parents who loved them and helped them learn their way would most likely not understand the existence of a person who had an abusive parent it just does not compute, the reasons are valid to the one who left and they have no need nor desire to apologize for the path they have chosen.
Spirituality is a wonderful thing, having faith in hashem is a wonderful thing but organized religion just doesnt work for everyone.