Well, families group objects together.
Objects in a family can have different behaviors from each other.
Referencing a group allows you to use less events to pick out objects (saves you from having to create events for each object).
When you pick out an object this way and need to perform actions based upon their behavior, then you simply can't do it without extraneous steps that make the events crowded and difficult to change later.
Doing this defeats the whole point of Families.