I absolutely understand why a Plat sink is needed. Plat is constantly added to the DDO economy. Even if you don't count things like the explosion of plat that came from various loot exploits and the accidental hyperinflation caused by the one Cove season, every single quest that we run adds plat to the economy.
I think that the Auction House is a fantastic plat sink. In addition to getting a quick and convenient way to buy and sell items, we also get a spectacular plat sink because people end up pumping more money through the AH whenever plat availability spikes.
...but why do we need an Astral Shard sink? If Astral Shards are going to start dropping in most epic chests, then I can see the need. If Astral Shards are going to constantly be added to the DDO economy on a daily basis, then I could see the need. But Astral Shards currently only enter the DDO economy when someone spends real cash money to buy them.
Is the Shard Exchange a sign that Astral Shards are soon going to be as common as plat? Should we avoid buying Astral Shards because we'll soon be flooded with so many of them that we'll need a shard sink?