By now, I think that a significant portion of the people working for the state are interested in only their own benefit.
My wild guess (in the "Pull the numbers out of the ass"
school of thought):
10 % of state-employees are genuinely interested in the welfare of the public
This is balanced off by:
5 % are genuine crooks
20 % who are mainly interested in their own benefit (reach a better position, do less work)
25 % used to care, but have given up
40 % don't have a clue at all
The higher in the food chain, the more (criminal) energy you need to reach this level, the higher the number of crooks.
Now, introduce some people who have genuine interest in the public welfare (but don't have a clue). Lets say these people want to fight drugs, because they think drugs are bad. So they go ahead and do the wrong things, making drugs expensive. Now there is money to be made in the drugs business, and lots of it. So other people, who have to operate outside of the law end up with lots of money, money they can use to "connect" with the significant number of crooks in the system.
So, by now, I think what we see with regards to the drugs is just the ghost in the machine. It is a system which stabilizes itself. It was a slight imbalance in the system at the beginning, but it has become a large crack (no pun intended) by now.
And once you end up in this machine, there is no way out. Once you have, for example, taken money, there is no way to undo this. Everybody who has made this mistake, will become a part of the machine. No exit. One is open to blackmail. The system stabilizes itself.
I think this is a function of rules we have. To change this, we would need to change the rules of the system. But different rules mean different problems.
Famous for 15 megapixels - Gambling