I haven't been on IMVU in a good while and when I was, I mostly kept to myself. The last time I was on several months ago, there were a lot of furry rooms and rooms dedicated to other niches. In fact, I'd be surprised to see the kind of rooms you describe considering how IMVU staff are notorious for removing anything they don't like.
That said, I believe anyone should be able to make whatever room they want, people don't have to go in them if they don't want to. I'm personally not a fan of furries so I would stay out of rooms dedicated to them but I wouldn't try to stop someone from making one.
Also, lets make sure to keep this thread a-political or it'll get locked.