To be fair to the bloke, it's really tricky for a spiritual system to endorse and teach use of mind/boy altering substances.
And though avoidance for avoidance sake seems naive - in the absence of time enough or education enough to partake in something without appropriate awareness and understanding of its actions and effects..... then it might be a good temporary rule of thumb.
Even if he did think it had merit, it would surely take a whole volume of its own and be an advanced stage after much progress on other parts of self development (for a system to endorse it).
I prefer the approach of strictly avoiding social usage unless its the rarest of occasions, just because the dynamics of motive within groups can detach oneself from appropriate focus (situational awareness (inner and outer), dosage and symptom record keeping, substance quality control, subject matter knowledge recall) that seems required for 'use' of substances for spiritual development.
To me the most compelling reason is the only reason needed, health, and I think the only reason sugar and alcohol are rather disastrous to our health is just because its so prevalent and ingrained in our cultures that its use is way over the top, used as a superficial bandaid for woes (hunger, emotion, stress). Peoples inability to exert self control in diet, distraction and entertainment are probably the main reason the more powerful substances remain illegal! History shows that if a society is vulnerable to addictions (see the
Opium Wars
) then it is prone to fall to them, either at their own hand or the hand of another. So I don't like the 'avoid' argument, but I understand its place, and how it impacts me and my actions to its topic. I think it will always be an individuals decision, and is not really something which should be promoted, or denied, at the level of the individual.
