It's never been a secret that a conversion to virtual currency would prevent the duping of gold and checks in large amounts. Mesanna has commented to this several times at both our in game meet and greets and real world meetups. That's an added benefit of not having currency as a physical object in the game in large amounts. The other reasons I mentioned are valid as well, as those are concerns we've heard from players in those very same forums. Duping has always been an issue, and one we try combat as soon as we have the information we need to combat it (people are generally not really willing to share those details, if you are feel free to contact us).
I also pride myself on being as up front as I can be when players ask questions about upcoming features and change. Insinuating that I would deliberately attempt to mislead or "cover up" anything when interacting with a community I've spent the better part of my professional life building a relationship with is simply not unfounded.