As long as the chat is within the guidelines (and keeping in mind that we have no proof of ages, etc.), general chatting is fine.
If you don't like the conversation that you're "walking into" in the main chat area, state what it is you would like to discuss and go to another room or create one? Chances are someone will follow or be along soon enough.
For instance, I went into chat the other day and, and today. There was existing chat going on. I jumped in because I was incoming. If I'd have chose not to because I wasn't "in the mood", I could've gone to another room.
The general chat areas can have, and will have, a hodgepodge of discussion and even silliness. That's OK.

There's enough rooms to accomodate the different needs.
It wasn't my place to walk into an existing conversation and say, "I don't want y'all to talk about this because I don't like it." I could've said, "I'm in such and such a place and going to go to such and such if anyone can chat with me."
On the same note, if a few are in the general chat area talking seriously, those incoming who want to be "light" should move on to social.
It should flow with what is existing when we enter the chat area, I think. For instance, if I had been in chat having serious discussions and one or two came in that strictly wanted social chat and not contribute to the existing chat, they could go on to social, those for support meet in support, etc. It's all about using the rooms. If we go in the general room until others come in and it becomes a strictly social, supportive, etc. convo, it would be appropriate to move the conversation as others come in showing diverse needs?
I guess it's just about acceptance and accomodation.
All that said, those who know they're meeting for a "social time" should meet in social. The same should be for support, etc...if it's known ahead of time.
Chat can be great for all if we use what we have and need to make it that way.
KD