In addition, it is clear that you wither do not know the notion of opportunity costs or do not apply it in this case.
The basic premise is wrong. An increase or decrease in the value of a house (or a stock or a painting) is not a profit or a loss if the property is not sold. If you stay in the house during a market downturn you have lost nothing. Don't believe me? Try to get the IRS to accept a loss on your next return if your home value dips below what you paid.