I also know I'd be miserable in such a household, and the reason why hit me as I was driving Warren home.
I spent the first 3.5 years of my life in a household with four adults (two couples -- my parents and Dad's parents, one me, one dog). Having two sets of parents was very awkward, especially when their ideals clashed. The best cook wasn't always the person who did the cooking, causing us to eat some really awful stuff at times. The women always got stuck with cleaning; this stuck with me so hard that to this day I have an aversion to doing housework.
Having two female "heads of household" meant they rarely agreed on decor. Granted, one owned the place, but the other wanted to assert herself, too, but couldn't.
Having five people crammed into three bedrooms also meant there was a notable lack of privacy. I was the only one with a private room, but even that wasn't really private, as it was a "temporary" room with a door that opened when the grownups felt like it.
My lack of privacy continued even after Mom, Dad, and I moved out. Mom and Dad had the wall in back of the bookshelf separating our rooms removed so they could see into my bedroom. When I was nearly seven and we moved into our own house I had limited privacy. I wasn't allowed to close my bedroom door, so the only time I got to be alone was when everyone else was downstairs or in the bathroom, or on those rare occasions when they'd let me stay at home alone for a few hours.
Now that I'm a grownup I can have privacy. I don't have people trying to force me to be naked or half-naked in front of them. I don't have people complaining about my watching TV too late, or about my not wanting to watch TV because I'm engrossed in a good book. I can close the door, and nobody can get in without a key. I like that. Heck, I cherish that.
If I can't be totally alone for a while I go nutty. In jobs where I'm in a cubicle and don't get visual privacy, I have to go someplace where I can close a door and breathe easy for a few minutes. I can deal with sharing hotel rooms because of cost, but if I can afford the luxury I prefer my own room. I can deal with a pet and an SO sleeping in my house, but I still have to close the door to outside psyches at least once a day just to retain mine.