The allure of it is irresistible to some people. The forbidden, illicit nature of it is attractive to them. Just like alcohol, there is the social aspect as well. The rituals involved, the subculture. It can be enticing. When you're young you also think nothing can hurt you, so why not have a dabble.
I dabbled in cocaine for a few years in my 20s. I was a fiend while doing it, but never craved it when not doing it. It made me drink more and chain smoke cigarettes, so I always felt like shit the next day. It was a weekend thing. Eventually I just got sick of feeling like shit.
I actually don't think cocaine is as bad as itsmade out to be. It's a stimulant derived from a plant. It should be legal, controlled for purity and taxed. Everything in moderation, even heroin ( which I never did).