This is an excellent step toward ending the massive demonizing from 80 years of the world's largest propaganda campaign.  It's even more difficult than  author, Walker, imagines though, since he presents one of the those false assumptions as if were gospel, saying:

>>>"our energy should be spent on how to talk with our children about the danger to their brain development that pot presents." 

There has been intensive research on marijuana consumption and brain development.   One early study appeared to have shown adolescents who smoked marijuana ended up with less IQ than non-consumers.  -  This was quickly debunked when it was found they had not controlled for socio-economic conditions.  -  It turns out the lower IQs were due to poverty, not very surprising.

But the idea stuck and even though all subsequent research has failed to find any proof of long-lasting harms for teens (or anyone else), people  continue to mislead with the idea, intentionally or not.