dunno what exactly it is about facebook... but having participated in a bunch of orchid groups on facebook, i've not seen the kind of valuable content generated by the group members that i've seen here on the forum. If ones' desire is seeing pretty plants, then yes, facebook appears to be a more current technology that folks are using to do that... but that's about the extent of the content. I for one hope that the folks on this forum don't evaporate in favor of mere picture posting and "wow that's nice" posts...
There are a few professional growers on Facebook, but they are not there to share or gain information, they're there for marketing purposes. Posting pictures of pretty flowers draws sales from a bigger population.
I have a "Growing Orchids in Semi-Hydroponics" group on FB, and if you think folks research posts more there before asking the same questions over and over, you're nuts. Likewise, the level of the civility is determined by the personality of the posters and the rigidity of the moderators.
Shocking dropoff compared the activity 10 or even 6 years ago.