Me! (For the most part, anyway.)
I did own a house that I lived in for 4.5 years. At the time, I loved my little house and was very open to the possibility of growing old in it. Then the market went up sharply, and I started thinking about how nice it would be to have all that money in my bank account. I sold the house, went back to apartment living, and ended up using the money to purchase 3 rental houses. Owned them for about 18 months while the market continued it's strong upward journey. Before long, I started weighing the thought of all that lovely equity I had built in a very short space of time, against the long-term liabilities of owning 3 houses. I sold them and haven't looked back.
Owning was fun and while I wouldn't rule it out again in the future, I really do like the lack of responsibility and liability that comes with renting. Being single, I don't have a family to house, or another person to think of. I suits me quite well. I do think that if you plan on being a lifelong renter, you also have to be open to being adaptable as to what kind of places you live in, and where you live. At some point, my current rental will probably no longer be a rental, due to the type of property and the age of the owner. Rent in the Bay Area has risen so sharply that when I have to move out, it will almost certainly be to another area. I'm open to change, and find the challenge of meeting it interesting.