I suggest that our free will prevents G-d from interfering. He has given us the freedom to do good or evil. To punish or reward in this world would take away free will because it would be obvious that evil people die horrifying painful deaths. Thus everyone would be good to avoid this inevitable punishment. In fact, just the opposite seems to occur.
Many evil people live healthy lives and many good die young.
I think this whole idea of G-d punishing the evil in this world and rewarding the good comes from the siddur quoting the Torah. After the Shema we recite a couple of blessings. If we obey and plant fields, He'll deliver what we need to help us survive. If we obey Him, but don't plant, G-d's rain will fall on empty fields. If we disobey, but we plant anyway, we may get rain because of the good of our neighbors.