[myownpetard]

> what's stopping them from doing it again tomorrow?

Giving medical help to a drug addict is more likely to reduce the likelihood that they commit another crime than giving them a criminal record.

[nitrogen]

Anecdotally, I can confirm this by seeing someone who made one very real but economically insignificant mistake have their career ruined for years over a misdemeanor charge. They needed financial and emotional help. Instead they got a plea bargain steamroller, no chance to talk to counsel, etc.