Sure those assets should be counted in a calculation of net worth. However, are we willing to liquidate those assets to make payments on our debts?
Would you have us hand the Eglin AFB deed to the Chinese instead of making an interest payment? Are you interested in giving our National Forests to the Saudis? How would you feel about visiting our nation's capitol and finding that the buildings there were owned by the Japanese because we owed them a bunch of money?
Unless these assets are on the table as collateral, then they should be kept off the books for the purposes of this discussion.
When you assess your financial well being, do you only consider your debt or do you also include the things you own? Are you better off with no debt and no IRA or with $10,000 in debt and $200,000 in an IRA?