Lacking? The incentives are in geared towards a high rate with lots of deductions, certainly on the business side. If I'm running a business I don't want a low rate or low regulation - I want a high rate with loopholes narrowly tailored to whatever I'm doing and a high regulatory burden. Politicians want exactly the same thing.

It's not exactly the same with non-business tax rates but it's not that far off either - see the deduction for SALT.