It never made sense to me, even in my early 20s. But I'm short on time and will borrow words from this guy....
This only explains part of the reasons why its not a cornerstone to wealth..
Imagine a broker trying to sell you on the following investment:
A fund that if held over 30 years will probably net you not more than the rate of inflation. You, the average person, are lucky because you can borrow to get into this fund; you can pony-up 20% or more of its value but you will need to borrow a couple of points above the current inflation rate to do that. To get into the fund will cost you even more if you can't part with at least 20% cash. And by the way this is both a front load and back load fund, as it will cost you significant transactional costs to get into this fund (closing fees, taxes, etc.) and you will probably pay at least 6% to exit the fund in the future. And then there's an average maintenance cost of 1 to 3 percent per year, just to keep the fund in good shape. And you will always be paying taxes on the value of the fund while you have it.
The benefits of leveraging to get into this fund? Instead of paying certain taxes to the U.S. and your state, you get to pay that money to a banker. Any profit you have on selling this fund can be rolled tax free into a similar fund only. And after you've paid off what you borrowed just to get into the game, you own the fund outright, subject to those same taxes and maintenance which will never go away.
You'd have to be crazy to 'invest' in such a fund.
But for a house this is something many of us are willing to do because it is more than an investment. A house is a terrible tax shelter, probably will get horrible returns over time, costly on a year to year basis and for most people is probably not the best diversification strategy (holding REITS might be better). But it is an asset that is (or someday will be) ours -- we are the CEO of it and can to some limited extent determine its destiny.
Counting on a home for retirement? If it's got a nice porch and an idyllic view -- perhaps. But more important will be the (hopefully) many wonderful years spent in that home where it was one of many places a family has over the course of decades been able to convert earned money into valuable assets.
A home is probably one of the few tangible assets most people will ever be able to own and control, an asset that has at least a chance of holding its value over time. Just like most financial options available to most people it is really quite costly.