Tax policy isn't set by moral arguments, it's set by government need for revenue which is then tweaked by political pressure groups.
The reason why you can deduct mortgage interest but not rent has nothing to do with fairness, which is undefined and a massively ambiguous term, but because banks, which are the primary beneficiaries of mortgage subsidies, have a lot more political power in Washington than landlords, who would be the primary beneficiaries of national rent subsidies.
For small, opening (usually developing) economies the matter is different, and they should have more capital controls accordingly.
That’s an intriguing comment. Can you explain further?
For states like the USA that print their own currency and enjoy tremendous global demand for their currency, taxes are less about revenue and more about controlling behavior and unemployment outcomes. Some argue that taxes are just a way to force demand for a currency the government has a monopoly on to ensure it always has _some_ value.
(Note: this is a rather polarizing theory and still somewhat young. The US Fed pulled off printing trillions last year and things haven't gone to hell yet do there's something there )
For a house, your net worth hasn't decreased by the cost of the house. A company wouldn't be able to deduct that. They can deduct for assets that depreciate.
Real estate tends to appreciate in value, especially in cities. The company would have to get unlucky with their real estate to be able to write off a loss. Buildings don't usually depreciate.
They could allow their buildings to fall into a state of disrepair, hoping it would lower their value. But why would they? The can deduct the repairs. It's a legitimate expense.
I’m not an accountant, but I’ve studied enough of it in University to be dangerous.
Depreciation isn't a cheat code that lets you avoid tax on profit. If you depreciate the building more than its actual market value depreciation, you owe back what you deducted when you sell the building.
The personal exemptions are a sham and do not reflect the reality of high cost of living areas.