Yes because the banks lobbied for it and got a lot of things deductible. We should have a very low flat tax and no deductions, period. Any time you carve out “special” exemptions and deductions you create an us vs them scenario. You only want it because you benefit from it (as do I). We, as conservatives, have to move beyond what only benefits us and do what is right.
But you still have to define income, don't you? And that definition has at its core the exact same situation you claim in untenable. Because any definition of income is inherently just another way of describing the deductions.
But now I understand your point of view - you are enamored with flat taxes and ignore the problem of defining taxable income.