I have to agree that giving people prison time for possession is a waste of resources.
If the police didn't spend half of their time dealing with drug arrests, then they could use that time to actually reduce other crime.
I would prefer that the penalties for crimes like theft, etc. be doubled and actually enforced while not wasting time on possession and other drug only issues.
This reminds me of "The Wire" where the police gave the drug dealers a non-enforcement zone. The dealers and druggies could operate freely in that zone away from most residents, businesses, and schools. This policy gave the police more time to enforce crimes that affected other people outside the zone. As in real life, when the politicians found out about this policy, it was cancelled.