That's a few joints as best, are we really declaring people as hopeless addicts for having more than a handful of joints on them? This seems similar to saying someone should never be allowed to have more than an 1/8th of alcohol on them at any time. Seems silly when put in perspective of what drugs are quantities are already legal.
I guess my point is we allow people to buy handles of alcohol (a much more problematic and harmful drug) at a time, even though consumption at that rate is also problematic. So why should we treat marijuana differently?