If this sort of movement didn't surface, thousands of stupid people around the world would conform to something else instead. Probably something that "requires" that they do substances to fit in. Although these people are totally fucking annoying and don't really think logically, the important part is that, to a large degree, these people are harmless.
Does this sound like anything slightly bigger? Yes, that's right, it's just like a religion! Cliques are really like mini-religions. There's a congregation, there's a similar viewpoint, there's a need to conform, and, well, in terms of "idols," it's usually music or movie stars. Although there are sometimes violent fanatics that totally take things out of hand, the majority of people, despite the highly menacing permanent-marker X's on their hands, are mostly harmless.
This is why, while I can develop my own opinions, likes and dislikes, if there weren't things like religions or cliques or whatever, we'd have a lot more chaos. Stupid people wouldn't learn how to react to things. They'd be very confused, they'd feel left out, they might become violent toward themselves and others.
But then again, if you really think you're smart, I don't think you need to rely on groups of people to develop your ideas and habits. Making a group of friends is different, in that you're creating your own arrangement that works for you - you don't have to change yourself at all to fit into a group.
So yes. Think for yourself. Realize through facts that drugs fuck you up and are bad for you. You don't have to join a group just to form and push beliefs. But if you don't have any beliefs or your own, by all means, go ahead.