Richard,
Most people focus on the wrong thing when they think about mortgages. It's not the interest rate and tax benefits that make them interesting for younger people. It's the certainty of long term appreciation. Let me give you an extreme example from the early 70s. Back then I wrote a column Vogue magazine on personal finance--- I had to write about things very affluent people did.
So I wrote about the economics of second homes. Back then you could borrow money at 7 percent and save 2.3 percent in tax benefits, giving you a net cost of 4.7 percent. That was well below the annual appreciation rate for second homes in primo places. In effect, you were taking money out of your income pocket and it was magically appearing in your net worth pocket. The only issue was whether you could earn enough to cover the mortgage payments.
This relationship was strong for nearly three decades, weakening only recently.
Today, the vacation property case is weaker and the general residence case is weaker still, but if typical home prices track inflation (rather than exceed it) over the long term, your 6 percent mortgage will cost you 4 percent net of tax benefits and 3 percent of the remaining 4 percent payment will be offset by price inflation, leaving you with a 1 percent out of pocket cost. (The 3 percent and amortization will go directly to your net worth.)
Since this cost is also fixed, it makes your mortgage a very nice hedge against inflation. If you use sophisticated financial planning software such as ESPlanner it generally shows that owning a mortgaged home will increase your lifetime ability to consume rather than decrease it.
As with most things, there are some very specific caveats. Having a mortgaged home works best when you are young, working and in a high tax bracket.
Being young allows you to ride inflation better than being old.
Working means you're making payments with labor earnings, not dividends and interest.
And being in a high tax bracket means you'll get that important tax benefit. Many middle income (and virtually all realtors!) assume that you'll have tax benefits galore from home ownership. But if you live in a lower cost area it's very possible that the sum of your mortgage interest and real estate taxes will be less than the standard deduction on a joint return, $10,700 this year, so there would be no real tax benefit to ownership.
Like you, I have an aversion to debt. Older people certainly should be because (1) they have less time for inflation to work in their favor, (2) they often don't have itemizable tax deductions because they've paid their mortgages down, and (3) they often have to make mortgage payments from investment income. All three factors make mortgages a poor deal for people who are approaching retirement or retired.
Scott