Your first claim is illogical. THC is an insecticide, yet not a single human has ever died from consuming cannabis. NOTHING is "Good" or "Bad" without proper context.
"Suggest" is not a very convincing word to me. Sounds more like a hypothesis than a conclusion. I highly doubt any ethics board would approve a double-blind clinical trial exploring how much coffee consumption is required to kill a human fetus in utero. Who are these monstrous Danish scientists!?
You're absolutely right -- everything turns to poison in excess.
Fun fact about THC though: "[...] babies of women who used cannabis at least once per week before and throughout pregnancy were 216 g lighter than those of non-users, had significantly shorter birth lengths and smaller head circumferences."
That's still more hypothesis, not conclusion. "Self-completed questionnaire on use of cannabis before and during pregnancy." = Observational study = result can ONLY be a hypothesis.
It's right there in the conclusion "may be associated" = "they do not know if this is true at all".
Next step would be to run a double-blind clinical trial, and have an unknown-half of the subjects smoke pot and compare that to the control to test if their hypothesis is true or not. Until then, it's only conjecture.
"Suggest" is not a very convincing word to me. Sounds more like a hypothesis than a conclusion. I highly doubt any ethics board would approve a double-blind clinical trial exploring how much coffee consumption is required to kill a human fetus in utero. Who are these monstrous Danish scientists!?