I do not understand why a FC passenger would want to board before the rest of the herd knowing that upon preboarding, he/she has to put up with the disturbance caused by slow-moving coach crowd (especially if your have an aisle seat in FC).

I would rather have the airline seat people in coach before inviting their FC passengers on board. The only drawback to this procedure would be that FC passengers would not be able to enjoy their pre-flight drinks that are anyways overrated.