I have been a Beatles and Lennon fan since 1963, and I cannot recall any of the band advocating drugs or alcohol as something thier 'followers' should indulge in.
Paul McCartney, when discussing his first use of LSD famously told a journalist that the 'responsibility' to fans was not his, but the media's - McCartney promised not to tell anyone if the journalist didn't. Guess who told people?
Musicians don't ask to be role models, or set themselves up as such. Very few seriously advocate drug use, unless to establish a quick headline, or underline a 'rebel' lifestyle.
There are dozens of public figures, a lot of whom are chosen and paid by the public who lead dreadful desolute lives while preaching sanctity to all - and no-one could argue that The Beatles did far more good, financially and culturally for us, than harm.