What is a tax reform and why are there countries that do not dare to do it?

To harmonize the tax system to promote trade and investment is a new goal of the tax reform. As long as we have known in economics, the higher rate of income taxes will kill jobs. The lower corporate taxes will increase competitiveness. But countries still use tax wall to protect the domestic producers. They use structural taxes like alcohol or tabacco to increase government revenues.Less countries use tax to correct the distribution of income and the degraded environment. The conflict of goals makes it hard for politicians to do it.