There are various taxes that work that way. Depending on how high they are (and how high the taxes that work in the opposite way are) it works better or worse. The difference between rich and poor is not the same everywhere on the planet.
Then rape the women and molest the children in the process, then kill them all when you're done; it is as moral as your proposal, just finishing the sentence. "How is this a bad idea again", you say?
Sorry, it is not by intention, probably cultural difference interpreting the same words in different ways. What is the second comment that looks out of line?