I'm really talking about it in the sense that it makes sense to own it at a certain price. If I buy a $200,000 home instead of renting, I'm deciding that it is an investment worth owning. I may not expect it to appreciate and maybe I even think it would depreciate, but I must believe that I would have more for my money in the end than in paying someone else who owns it rent for the same property.
In the sense that is a investment, people who own homes are not aware of the massive liability they have assumed -- or are dependent on others meeting -- in order for that calculation to work out. If they were aware of that, many homes would be worthless (because they are).