We are missing the private bedroom, shared kitchen/dining/living space that a lot of single people want. There are people I couldn't live with, but for the most part people crave some human contact and having the ability to grab a meal with a random person who happens to want to eat at the same time is nice.
When you are married (or acting like married) a shared bedroom is good. However single people often want that personal/private space all to themselves.
There's probably a selection bias in that people who opt-out of dating/relationships probably just want to be left alone most of the time. I doubt there's a huge overlap between people who want to share meals with strangers and people who remain single.
In college in the university dorms I was logistically and emotionally fine day to day sharing a room with a friend and a hall bathroom with a hall of acquaintances, although in hindsight the price was absurdly inflated for that amount of real estate.
Yep, at the moment renting a room at UNC costs 2200 a month if you share it, nearly twice the mortgage on a 3 bedroom house. There's some disease in the american economy where cost cutting code actions magically inflate costs, and we buy it.
When you are married (or acting like married) a shared bedroom is good. However single people often want that personal/private space all to themselves.