I say legalize them. It'll take nonviolent offenders out of prison, reduce the "need" and power of cartels (think Prohibition), and make things safer for users, not having to risk buying stuff from an armed criminal cartel/gang member or their friendly neighborhood drug dealer, and also by allowing them to buy from reputable sellers with quality control, not some impure, spiked nonsense from the previously mentioned scumbags. Often times it's not the drug itself being bad that kills addicts, but things added to the drugs to make them stronger/cheaper/etc.
Now, with that said, legalizing drugs doesn't mean that anyone can do them anywhere at any time. Jobs could still say that you have to be able to pass a drug test; you don't want cops and firefighters working while high. Now, some drugs will stay in your system for a long enough period of time that you can't do them on the weekends and show up for work on Monday and pass a drug test. With alcohol, while you can't be drunk on the job, the vast majority of jobs don't care if you drink after hours or on the weekends, but you wouldn't show up as intoxicated on a test from drinking over the weekend, so it's not really relevant. If you do some drugs on the weekend, you can fail a drug test during the week, which means that these jobs can effectively not only say you can't be high on the job, but you can't use these drugs at all, as if you used them at all, you'd fail the test the same as if you used on the job.