Not sure what the DoH/L end game content will be like but I think it was stated that they will have their own goal for end-game. They just won't see the main battle story, and for obvious reason it make sense. If you chose to be a crafter, then you should not be expected to go fighting endgame bosses, or for the love of the twelve go parley with bosses.

They can make a lot of interesting endgame related content for the DoH/L so that people who enjoy this type of class/gameplay might enjoy. Yes they will be support classes, because they support battle classes in their trade but doesn't mean that support isn't vital. I play a battle class mainly but I hope they come out with support battle classes because that is the gameplay I prefer. Does it mean that I am less important than another type of battle class? no, I just provide my help in another fashion.

Think of DoH/L in the same way.