If there was a class to craft shards, they would need to make a whole new crafting class just for that, and even then they'd still need to have a material to craft that.
I think its fine the way it is, unless you grind for some reason (logs, achievements?) you only need a couple of shards. Just take a few minutes and you have enough shards/crystals for a couple of crafts. Or you can have 2 gathering retainers and let them gather the shards/crystals for you ^^