Your simplistic and incorrect analysis is wrong. SB91 has not even been fully implemented. But since you insist on proffering your opinion, how about some cites and links to your proof? Do you even know how much it costs to lock someone up, not just financially to the state, but to the person imprisoned, to his or her family, to society when he or she can't work, the cost of medical and mental health treatment due to the effects of incarceration, the human cost to the people incarcerated for drug use and their families? 
"Gutierrez said Wednesday during an overview that even though crime rates and recidivism rates in Alaska are decreasing, the state has the third fastest growing prison population in the country. As of January, the DOC was operating at 101 percent of capacity. The recidivism rate is 63 percent. “Alaskans deserve better than that,” she said." http://www.alaskacommons.com/2015/02/18/with-alaskas-prison-population-rise-legislators-look-ways-decrease-recidivism/