I could understand your response if the parent were speaking about LSD or bath salts or something else that have been known to give people bad, destructive trips. But shrooms?
Psilocybin is known as the gentlest and most enjoyable psychedelic there is. Adverse reactions are rare, and as far as I know nobody has ever come out of a shroom trip with their brains scrambled. Personally, I find that the experience isn't so much a "trip", but rather a gentle, beautiful and interesting set of visual effects. I don't hallucinate people or supernatural beings, but I do see colours around the edges of things, and repeating fractal patterns everywhere, and enjoy a strangely improved acuity of vision.
Shrooms are also a type of drug where you can derive a psychological benefit from very small doses (or microdoses) that essentially provides no "trip" at all. There's promising research showing benefits for depression and PTSD. Not to mention that psilocybin is not addictive.