I think what you are seeing is a wave of exhaustion that is going through the online art communities. People are desperately trying to sell artwork and are adding the work to multiple sites to gain more exposure. Unfortunately, this takes more time to manage and leaves less time to socialize. In general, I have noticed a decline in comments and replies across all of the art sites. Along with this the communities, groups and other social activities are dwindling. Newcomers have a tendency to be more active for a few months then they also tire and fall off. However, every site has their die hards who try and keep things moving and we should be thankful to those who do. It is the sense of community that will bring us together and make us strong and a strong community will draw more people and not just artist but customers also...
Thanks for staying persistent...