Why do we want people to buy houses? It incurs transaction costs and makes it difficult for people to relocate to be near their jobs and such. It seems like we should optimize solely for the cost of meeting people's needs - either by paying rent or by owning - compared to the sale value of their labor.
Renting contains a lot of inefficiencies. If you don't like your bathroom faucet and you own your home, you go to Home Depot and buy a new faucet. If you rent, that's not yours to change and now you have to negotiate with the landlord or live with it. Also, you might not want to put money into a building you don't own, but the landlord wouldn't want to put money into a building they don't live in. There are a lot of perverse incentives and transaction costs.
That doesn't mean renting should be prohibited -- if you'll only be somewhere temporarily or you can't afford to buy then you still need somewhere to live -- but in general it's something we'd want policies not to encourage.
