I've been on the site nearly 5 years and get ignored in chat regularly. Mostly, in fact.
There are enough people to go into other rooms, but no one wants to for the most part, that's all there is to it. People want to go where there are other people.
And since the Lounge is the default room, that's where people go straight into, especially new users.
Also considering that they have instituted the donate requirements to get into the other rooms now, that means less people have access to other areas, which only encourages people to stay in the Lounge (or Bible Study) even more.