We need a social context for how and when to take them (beyond "let's partee!"). If you look at cultures with a long history of psychedelic practice, the use tends to be very ritualized, with a lot of specific context as to when they are taken, how often, and for what purposes. There is also substantial effort taken to integrate the experiences.
If you just take a bunch of stuff at a party and believe everything you experience is literally true, sure you are in a risky position. We need to push people towards communally-meaningful experiences with integration afterwards, and away from just blasting their minds into space willy-nilly.
We can't do this while they are illegal though. Keeping them illegal encourages the worst kinds of uses, with no oversight or integration or cultural meaning.
The cultures with a long history of psychedelic practice are just as bad for spiritualist bullshit as this new age culture. Actually, most of the bullshit these New Spiritualists spout is taken directly from these cultures; chakras, spirits, "bad energy", shamanism, etc. all comes from those cultures.
