Your loop-hole doesn't make any sense. Mortgage interest is deducted against income but that doesn't make your loan "free" from cost since the tax rate isn't 1

Your loop-hole doesn't make any sense. Mortgage interest is deducted against income but that doesn't make your loan "free" from cost since the tax rate isn't 100%. Example: $1000 in net operating income, $500 in mortgage interest, 25% tax rate Taxes paid = (1000 - 500) * 0.25 = $125