There is no one on APUG trying to "own" dry plate. The forum is open to all!
There is certainly no one at GEH trying to "own" it either. The biggest site directed to dry plate, paper film and etc. is "The Light Farm" owned and operated by Denise. GEH has plans to have more broadly based workshops on dry "plate" photography and also wet plate. See their workshop schedule.
The workshops given at GEH show every student how easy dry plate is and how inexpensive.