A court hearing, possibly of several days, is reported by a hack in a few lines. I suggest we should tread warily before commenting
However
The issue is he took a drug that had an effect on his flying. For all we know, and on the balance of probability given that he was an habitual user of illicit drugs, he often took such drugs which wore off before he flew or had no appreciable effect. It may well be, as often happens with such illegally produced substances, that this one time the drug had an unexpected effect or duration - clearly it was unusual as he was texting about it.
IMHO his aviation 'crime' was taking any drug without declaring and grounding himself initially - it matters not to me whether it was penicillin or ecstacy. But that should be what he is punished for. To remove someone's career when another person might get away with a warning is not appropriate.
As more such drugs become legal in more countries this is an issue the profession and the medical profession will need to address. How many pilots legally smoke cannabis in Colorado and fly the next day? Do they disclose to their AME? Should they?