A large amount of Crystal Energy in the game right now is likely being hoarded by a relatively small number of players. I believe that, for the most part, this isn't out of any deliberate intent but simply due to a lack of reason to convert to Crowns. These players sell Energy when they need Crowns but otherwise keep most of their money in an Energy format. As a result, most of the high end trades are done in Crystal Energy instead of Crowns purely out of convenience. If Energy could not be traded between players then the Crowns / Energy market would see a lot more activity and the economy would equalize more to balance between the two instead of leaning heavily toward Energy as it seems to be right now.
While I'm not one of those players who thinks the economy is broken (I'm fine with the Crowns/Energy market being player driven and falling wherever it does) a number of players appear to feel differently. I think that forcing players to deal only in Crowns would stabilize the Energy market a lot faster.
I agree with this.