OK: assume you locked in a 30-year loan 2 years ago, because it didn't even occur to you to get a 15, or you couldn't afford it.

Now, you're set in your place for another 10 years. You didn't expect that kind of stability, but time just flies.

So in 12 years, you'll still need 18 years to finish paying it off. There's no point in refinancing, since rates are higher now.

Had you gotten the 15-year, you'd be within 3 years of zero mortgage payments. If you're in high tech, quite likely you'll be earning much more after 12 years, and that monthly payment will be no problem.

You're right, the "quite likely" does do a lot of work here. You're taking a risk. No argument there.

> if you have a cash flow problem in 5 years and default

That isn't a problem in practice. Most banks don't want to foreclose and they'll restructure your loan, as long as you're not a deadbeat. And in 5 years, you'll have paid down the principal, at least a little. More than you would have with a 30.