Joey, since you asked. And I'll try to be very brief.
Not every one tries drugs just to be cool. For some it is an escape from the suffering they experience in their lives. Each person's path is unique, and none of us can know what another experiences. For instance, for a kid who lives each day with an abusive parent, whose life seems to be one of constant suffering, the few hours of bliss drugs offer can be very attractive. For others, it may be on some level part of a spiritual search; the experience of a meaningful change in perception. Again, each person's life is different. For some, there is a strong desire for a spiritual experience, or spiritual understanding of life, that the religious path of their parents, or lack thereof, did not provide. For them, drugs may provide the first hint that there are indeed alternative spiritual paths. And then there are those, as you have stated, who only try drugs because their friends do and they think it's cool.
In the sixties, LSD opened the doors of perception to many people who found the experience of perceiving the world from such a totally different perspective to be a spiritual awakening. As a result, many of them soon found spiritual paths to follow and left the drugs behind. Others did not.
Mushrooms, peyote, etc. have been integral to various spiritual practices throughout history. Under the guidance of a spiritual advisor, as for instance in the American Indian peyote cults of the nineteenth century, they can provide that glimpse of the sacred.
Personally, I would not advise anyone to use drugs. For those who seek spiritual experience, there are many spiritual practices and teachers whose guidance will lead to a spiritual path deeper and more profound than that of drugs. For those who wish to escape the suffering of their lives, there are also paths available; a change in environment, counseling, spiritual teachers, etc.
I guess my point is that for some, drugs may be a valuable teacher, a signpost along the way. For some others, drugs may be a warning sign of serious problems in one's life that need addressing.
In the interest in being brief , I'll stop here.