people do drugs for different reasons, one of them being to have fun. i've done my share, and i've never had any other reason than to get ****ed up and have a laugh. and here i am, fairly succesfull and by no means addicted to anything (except tobacco, but i'll quit soon). it's the same with all drugs, including alcohol and tobacco. they can be used purely for pleasure, with no problems to escape nor no voids to fill.
then again if you do get addicted, you'll have a lot of trouble to stop using. i'm all for clean needles and (relatively) safe drugs for people who need them. after all, most of the addicts die due poor hygiene (dirty needles or HIV) or overdosing.