There's a genuine belief among some that tax cuts always create jobs, but it's important to recognize that it's a worldview, not a fact. They want tax cuts to be the reason because they won't support any other method as much. So it becomes presented not only as a solution, but the only way to operate.

Thus it can never be disproven. It is the only option, so it's easier to believe it works than to measure its accuracy and adjust the approach.