Marajuana, a non addictive drug versus Meth, a life ruiner among many other things.
You're basically saying all drugs are okay because people are lax with decriminalization (not even legalization) of a plant?
Your argument has shifted from people doing whatever they want to themselves with a single drug.
This argument would have been pretty valid if it was about crack, cocaine, ice (the big time stuff that you wanted legalized anyways)
I found only one hint on what your argument started at:
Rates of hard drug use (illicit drugs other than marijuana) among emergency room patients are substantially higher in states that have not decriminalized marijuana use. Experts speculate that this is because the lack of decriminalization may encourage the greater use of drugs that are even more dangerous than marijuana.
And even then, this proves that marijuana was the root (pun intended) of all evil.
And again, this deals with decriminalizing, which isn't legalization.
So unless your point was "People should be able to do whatever they want to themselves, therefore things should be decriminalized (not legal in any form; still allows such drugs to be fined/ permitted if caught with use) and be treated of their addiction instead of having rabid coke-heads running on the streets." I'm at a loss.
EDIT: But yeah, i think I'll go to bed. It's obvious your idea for the greater good rests within "what if's" and "maybe so's"