And the more permissive and readily available, children, the most vulnerable, will smoke it too. No doubt.
A federal system is a great way for people across the country to see what works and what doesn't. If, over the next 20-30 years, Colorado does really well and produces about the same number of good citizens as any other state, then marijuana use won't be an issue. If, on the other hand, Colorado slides into decline, perhaps people may decide that this experiment was a mistake.
A federal system is supposed to be a system that allows experimentation, if the voters choose it. I have no problem with this.