The thing is, they never actually legalized them. They decriminalized possession of small amounts of hard drugs, which has most of the downsides of legalization (less restraint on users) and most of the downsides of keeping them illegal (trade still in the hands of criminal gangs with no quality control, which is a major contributing factor to overdose deaths, and the cause of most drug-related crime even excluding the illegality of possession with intent to sell).