Nietzsche was weird. He was not an idealist but he posited this transcendent idea of "will" which is basically New Thought. But I'm not an expert on Nietzsche so maybe there is more nuance here.
There is a kernel of truth to New Thought and its kindred ideas -- if you believe in your future success, you are less likely to become discouraged. In many cases success is claimed by those who are willing to fail over, and over, and over, and over again until they succeed. But that's a brain hack, not metaphysics. Your thoughts have determined your behavior, which has increased your odds of success, which can then be retroactively interpreted as magic if you are so inclined.
As far as hand waving it away -- I think the burden of proof is on those who claim such an extraordinary thing as "our thoughts determine reality." I want to see someone actually bend a spoon without touching it. Then we'll talk.