Ok here are my thoughts about this.
1. waaaaaay back on .com birthday threads were only made by friends of people. That's just how it was done and people still stuck around.
2. Most people in that list do not visit the forum anymore.
3. Most people do not even check the members section.
4. Why does it need to be done by a mod? After dealing with problem members, sorting out bugs this place has, moving threads, closing dupes and just generally trying to make this place run as smooth as possible you want to give us another job to do? If this is a "community" it shouldn't need to only be done by the people "driving the bus".