To argue that Allen Ginsberg’s poem “Howl” celebrates drug use, one can point to the opening words of the poem, “I saw the best minds of my generation.” What follows is an ebullient enumeration of what these brilliant people did. As the question notes, they used drugs, including peyote and marijuana. That Ginsberg views these drugs users as admirable suggests that he is, in as sense, celebrating drug use.
However, one could say that he’s mainly celebrating the lives of him and his friends. Drugs are a part of their lives, but they’re not the only part. There’s also music, intellectual debates, sex, travel, and so on.
Thus, to claim that Ginsberg is celebrating drug use might come across as inarticulate or sweeping. It suggests that the main point of the poem is to extoll drugs. There’s probably something more complicated going in “Howl.” Think about how drug use contributes to the alienated, fractured, thrilling, pulsating lives of Ginsberg’s milieu without him necessarily singling out drugs as specifically worth commemorating.
Of course, one could claim that Ginsberg romanticizes or glorifies drug use. Whatever his intentions, some might say that he makes it seem like drug use goes hand and hand with a certain kind of enticing, counterculture lifestyle. Ginsberg does not sugarcoat the impact of their rebellious behavior. It clearly has disturbing consequences. Yet abjection is not without its appeal.
Finally, to posit that “Howl” condemns drug use might prove trying—especially since Ginsberg explicitly promotes drug use in later texts and interviews.