Tax policy is something most people don't like to think about. The existing system has a tremendous amount of staying power. There is vested interest, but the biggest barrier is habit. Politicians say the best tax is an old tax which is familiar and accepted. There is a conservatism among folks that we know we can at least survive with the existing system, so why start wild experimentation.
Tax shifting is different.
The first thing we need to remember and communicate is that there is nothing about the tax system that is pre- ordained. It helps to tell people a bit of history. Take for example the history of U.S. corporate income tax. Go way back long ago to when the federal government got most of its revenues, up until about 1920, from tarrifs. At the state level almost everything came from the property tax.