With psychedelics, the failure modes are a lot worse.
I feel like psychedelics are karmic time-accelerators, by a factor of about 100-1000. The good news is that, in a way, this means that you can have a month's worth of experience in a few hours. The negative is that, if there's something negative about to ripen in the next six months, a trip can have you encountering it immediately and deprive you of the time to react to it and get the help, or make the changes, that you need.
Also, there's a perception that "meditation" is closed-eye sitting, and that you don't get to experience the external world while doing it. That's not entirely true. There are walking meditations, for just one example, and one of the goals of many meditative practices is to bring that meditative mind into your daily life. That's easier said than done; it's quite difficult, to tell the truth, and probably not desirable, for average working people, to bring the meditative mind into all aspects of daily life.
All that said, these drugs shouldn't be illegal (even for personal use, what a person wants to do with his or her own body isn't the state's business) and they definitely deserve more research. I think they have a lot of potential and deserve further study, and that the stigma/illegality do more harm (in terms of supply problems, set-and-setting issues) than good.