In theory, the basic exemptions for each dependent (including, for independent taxpayers, the taxpayer the self) serve a loosely analogous role.
But yes, businesses are treated somewhat differently (but mostly it's businesses, not corporations; an individual with business income and expenses can do the same as a corporation, at least to offset business income -- I forget whether business losses that exceed business income apply against other income, though ISTR they do and that's a key difference between hobby expenses (which can only offset hobby income) and business expenses.
But yes, businesses are treated somewhat differently (but mostly it's businesses, not corporations; an individual with business income and expenses can do the same as a corporation, at least to offset business income -- I forget whether business losses that exceed business income apply against other income, though ISTR they do and that's a key difference between hobby expenses (which can only offset hobby income) and business expenses.