Once you can get things from the ASAH that you can't get elsewhere except by having it drop for you - particularly powerful equipment that's usually BtCoA, which more casual or newer gamers can't see themselves being able to acquire by the legitimate route - you're essentially enabling the power gamers to make you real money; you're monetising the most problematic (but necessary) demographic in the playerbase. The power gamers - many of whom no longer spend any money with you at all, or nothing above their subscription (as a matter of pride as much as anything else) - go out and do the tough quests to get the really phat lootz. Anything surplus to their requirements gets dumped on the ASAH with an asking price of "lots" of shards.
A relative newbie or long-term casual player with a decent job and deep pockets comes onto the forums asking for gearing advice. They consider the answers and look at the long corollary list of raids they need to run a squillion times, or quests they need to farm, or challenges they have to play until their eyes bleed, and think "hell, I play four hours a week, I'm never going to get this stuff", and *then* they look at the ASAH and realise that for a $50 package of TP they can skip months of work and gear their toons to a decent standard.
What does this well-off but casual player do?
Almost certainly, they shell out for the TP and buy what's offered on the ASAH without ever setting foot in the raids. There are enough people for whom the time is worth WAY more than the money that this is a viable scenario. Turbine have then effectively monetised the efforts of the power gamers...
I mean, look at all the drama over the 3-tiered loot system and the people who really want EE gear but aren't up to the job of running EE quests (without the EE gear, or so the argument runs). What is most of this gear? Why, it's BtCoE! As the power gamers replace their old bound EE gear as new content comes out and dump their previous stuff on the ASAH, people pay shards for it. The power gamers - many of whom weren't going to spend any real money anyway - get "rewarded" by acquiring the ability to purchase items it's against their principles to spend actual cash on, the wealthier players get gear they wouldn't otherwise have been able to acquire and Turbine make a big pile of cash selling astral shards.
In many ways, it's really elegant. Turbine have developed a way of selling loot in the DDO Store that isn't "selling loot in the DDO Store".
To be sure, there'll be some backlash, but compare the likely outcome - in forum rage terms - of selling an ESoS for 5,000TP vs. allowing an ESoS to be sold on the ASAH by the player for whatever the market will bear. Apologists for the former would be in short supply. Apologists for the latter will be numerous. I can see the arguments already; "Well, they worked for the loot and they don't need it any more so they should be able to see some benefit for it instead of it just taking up bank space", or "It's the player getting the reward for their work, not Turbine"... but of course it is Turbine getting the reward for the player's work, in the form of someone paying for astral shards.
Alright, the ESoS is a deliberately emotive example and it's likely things wouldn't go that far, but it's a useful illustration, don't you think?
Once the thing takes off properly and the "creep" of what's permitted for sale on the ASAH begins, they'll be able to drop their percentage cut of shards and have people be grateful for it. The real horror of it for me is that I *am* one of those people who has money but no time, and - hand on heart, cards on the table - I'm not sure, for all that I think there's a danger of this system ripping the heart and soul out of the game, that I'll be able to resist. I'm a decent player, I think - no Hall of Famer, but solid - but with my meagre playing hours (4-6 logged-on hours a week, if I'm lucky) there's so much stuff I can't get that I'd love my toons to have. Honestly, I don't even *want* to run CitW (to take one example) but if I could blow a few dollars' worth of shards to get hold of a Sireth or Celestia... I'm really not sure I could stand on principle well enough to say no.
There's one use vet players could already make of the ASAH, which is trading bound items from one character to another. The shard cut that Turbine takes is essentially a fee for you posting an item and then buying it back on the toon you want to transfer it to. A slightly risky strategy, but not *that* risky if you're quick, and if you dual-box you could do it in two transactions for cheap if you don't want to take the chance of someone else snaffling it.