Since before recorded history, (i) the ecstasy of drug-induced experience has been explicated, analyzed, and glorified in poetic works.
In modern times, not just the ecstasy of the experience, but (ii) the thrill, status, financial benefit, and implementation of selling and distributing drugs has been glorified and explicated in poetry (read: rap, the mainstream poetry of the past 25 years).
Question: are either [bad / wrong / damaging to society] / [inherently immoral]?
For the former ((i)), since the ecstasy in question is a personal experience, it is hard to imagine it as damaging to society. Certainly, the government-popularized myths of spontaneous insanity / stupidity / anti-social behavior would, if true, be an argument in favor of this conclusion. Unfortunately, most government propaganda about drugs is just that: propaganda. True, most illegal substances (with the exception, perhaps, of marijuana) can result in damaging and violent social behavior, but this does not distinguish them from legal substances (such as alcohol, cough syrup, dramamine, nutmeg, phalaris grass, "energy drinks," etc.) which, if abused, will likewise result in the same. Furthermore, emphasizing such downplays the potential benefits (the ills cured by ibogaine are far more severe and intransigent than those cured by ibuprofen, for example, though only the latter can be legally distributed within US borders).
For the latter ((ii)), a society which incites poetic descriptions of illegal behavior has clearly strayed in its imposition of order. For, the point of the formal imposition of forms of behavior (whether positive (drive on the right hand side of the road) or negative (do not murder)) is surely to benefit society as a whole. If said society "votes" for one form of behavior in its imposition of law and another in its consumption of art, this society exhibits a schizophrenia indicative of illness every bit as much as schizophrenia is a symptom of illness in the individual.
Consider, for example, two examples of socially imposed behavior: (i) driving on the right hand side of the road, (ii) failing to sell cocaine. If one violates either of these mandates (driving on the left hand side; selling cocaine) one will be punished, and perhaps imprisoned. Nevertheless, the two forms of behavior are represented quite differently in the arts. For the former, I know of no poetry or other form of artistic expression which systematically glorifies or encourages driving on the left hand side of the road. For the latter, not only are there numerous poems / songs / raps which encourage and glorify the practice of selling cocaine, but there are likewise numerous poems, etc. (dating at least to the romantics) which glorify the practice of consuming cocaine.
Now, why this asymmetrical opposition to the imposition of social structure in the two cases? My personal view: the former (driving on the the right hand side of the road) represents a legitimate problem of social coordination - we need social organization here (whether explicitly codified in law or no) to fulfill our ends; the latter (failing to sell cocaine) only fulfills the ends of certain conservative / selfish / (most importantly) ignorant segments of society.
The point: art which encourages violating the law is an offense to all of us (because it is in all our interests that the law is obeyed, that is why we made it the law). Therefore, a society which engenders art which glorifies violating the law is a society which has implemented the wrong laws.