Why isn't Marijuana/Cannabis/Hemp Legal yet?

The reasons are obvious, the positives are outstanding, the supporters are infinite, the opposers are slimming down, there are Jamaican ladies that are living to be 120. This is the only way to stop global warming, the fuel core is running out in 50 years, and this will be the only option. It has to be legalized within the next 50 years. It just has to be. Why is it taking so long!??! WHY IS THE GOVERNMENT SO STUPID?!