I think in the next 20-40 years laws will change, because its no longer necesarry that everyone works. Furthermore the now growing generation of people are much more open to things like canabis "bath salts".
In my opinion smoking canabis is a pretty accepted thing in the younger generation. Maybe they will keep this acceptance when they are in the position to change the laws.
In Europe the big politicals parties lost a lot of votes in the past years, parties like the "pirates" are voted by the younger ones. Maybe this political change will happen and will change our society as well.
When you look at the czech republic, they don´t even really care about people taking "drugs" nowerdays. I don´t know what the law is, but buying / posession and so on is not really controlled..
What i wanted to say, is that their is a change happening and you already see small parts of it, it just takes it time.