Home ownership is am important facet of "the American Dream" even though fewer and fewer people are able to achieve it. Why did it become a cornerstone of the Dream and why is it still?
The first, and obvious answer, is that it is a carrot to motivate labor. Just out of reach for more and more people, but an ever present symbol of having "arrived" being waved in the front of workers' faces.
More subtle, but just as important, and maybe more so, is the fact that while land has innate value (for the diverse life it supports), it does not produce wealth until its ownership changes. Creating the desire of home ownership greatly benefits those who have the wealth and power to wield the weaponry needed to sustain the (very, and only, human) construct of ownership of Creation, and can entice others to assume ownership of what cannot be owned.