The fact is that there is a social stigma towards illegal drugs, and it's a conglomerate ruling. So many people out there don't do their research into any type of drug, and just assume they are almost exclusively a negative force because of articles they've read in the paper about drug abusers performing ridiculously thoughtless acts.
Fundamentally, so many people, including most of the people i have met of my 'generation', believe all drug users are abusers, people acting self-destructively and with no consideration for the well being of others. We are labled and shunned, by typically ignorant morons, who have their own problems which in all liklihood are much worse, but generally more accepted by society. E.g binge drinking, complete lack of emotion, ignorance, stupidity, family problems, dellusions etc...
Of course loads of people abuse drugs, but i am so fucking sick of being categorised. in my job, people look down at me without knowing anything about me, i usually try to guess if they think i'm a self-destructive drug abuser, or violent binge drinker.