In many ways, it is like making prostitution legal and issuing licenses is: A confirmation of legality and a way to keep things clean and under control. Amsterdam is a great city with plenty of history, museums, and great stuff to do, but if the red light (and dope sellers) get out of hand, then you lose some of the more wealthy tourist types (like my parents) who would never go to a place like that because it is "too dangerous" for them.
Balance.
I found that in Macau last week too
