This is actually really on point, though. Cocaine, in the time that Conan Doyle was writing, wasn’t viewed as like the scourge of the earth the way it is today. It was actually originally heralded as a harmless pharmaceutical substance that could help cure (or at least alleviate) everything from the common cold to alcoholism. It was in throat lozenges and nasal sprays and used as a local anesthetic. People had literally no idea how addictive or dangerous it was, and it was available from regular chemists. There wasn’t a stigma about it until the late 1910s and -20s when medical professionals started to realize how harmful it had the potential to be (mostly because they all got addicted themselves; in the first wave of cocaine addicts a huge fraction of them were dentists). So Sherlock Holmes having a coke habit wasn’t nearly as taboo as people often assume it is. From the earlier stories it’s actually pretty clear that Conan Doyle didn’t even know what cocaine actually did, because he describes it the first time or two as having the same sort of effects as opium or other ‘downers,’ which is pretty much the opposite of what cocaine–being a stimulant–actually does. Somewhere along the line he was either corrected or tried it himself and realized he was wrong, because his portrayal of it does become more accurate, but I think that still goes to show how casual the attitude about it was at the time. So Holmes liked coke. So what? It speaks to for his need for mental stimulation, but it doesn’t make him a rule-breaking bad boy. At the time a coke habit wasn’t much more dramatic than smoking cigars.