Does the government realize putting people in jail for minor drug offences creates more criminals?

A lot of people who go to jail for minor drug offences like marijuana, end up coming out criminals, because they get "Turned-Out" in prison, most guys get forced to join a gang, and usually have to do something to prove themself like kill another gang member and it changes them. Spending three years with nothing but criminals is most likely going to turn you into one. There turning average calm stoners into criminals, and I thought the government was supposed to protect the people? And I'm not saying this happens to everyone, but it does happen to a lot of people.