I do get what the OP is saying. There are other RP venues in SL where people usually don't have a home/house (or if they do, it is not on that sim). The sim is one big public RP place, and, generally, the people are supposed to be there to RP. (Which doesn't always happen, of course. Some people love logging in to be afk for days in the middle of a public RP space). Some sims offer limited housing (in exchange for rent). In SL Gor, the fight for traffic seems to have given rise to some sort of obligation on the part of sim owners to offer big-ass homes for free, Gorean 'cities' looking more like US suburbia, a landscape dotted with little parcels than like an actual city. And people want big-ass rooms, for their 8 foot avi's, with 20 meters between them and the nearest other place where someone might RP, so they can toss out freebie bondage equipment.
Still, as a player, I do get why people might find it fun to have a 'home'. Even for RP purposes. I like having something like that, myself, even if it is tiny. It helps with immersion. And, of course, in SL Gor, you do have the owner-slave relationships. If someone wants to be a full-blown slave owner of a private kajira, they will likely want a place to 'keep her'.
But like I said, I do get where the OP is coming from. A bunch of people sitting afk in houses, perhaps sometimes engaging in their own private RP doesn't make for much of a 'city', if you ask me.