I am far from a chat expert (have only been there a couple of times), but I think it might take more than one or two visits to really get used to it, and for them to get used to you. I have found that to be true in our local herp society too. A few new people have complained about feeling lost or unwelcome there too. A few of us try to take extra time to try to include them, but unfortunately, we often get so caught up in our own discussions that we kind of forget. Or we just don't really know what to say to the new person. Some are just more outgoing than others. (I am talking about our local Society, but I feel it applies to all kinds of situations with new people joining a group).
I think it would be great if each group (real world or virtual) would take special measures to welcome newcomers, but human nature is such that we are often absorbed in our own world and only a few of us measure up in really reaching out. If I join a new group, I often lurk about for a while, waiting for some part of the conversation to turn to something I can contribute to, and become a part of. It doesn't always happen on the first attempt.
I can understand why snakemom would feel unwelcome when everyone left shortly after she arrived, and I can't say what the actual situation was that night. Maybe they were about ready to leave anyway, or were tired and didn't feel like starting a new conversation with somebody they didn't know at that time. Or maybe they had some other reason - I just don't know.
Again, I have not participated in the chat room enough to know if they really don't welcome new people, or how long it takes to become part of the group, or what the general protocol is in there. I just feel it wouldn't be fair to generalize after one or two visits with only a couple of people there.
But I do hope that you (snakemom) and others will get to feel a part of the community as time goes by.