Are you saying the legalization of alcohol and prescription drugs is a faulty policy? Would we be better off with all of it being illegal? Nicotine, Caffeine... are there any drugs you think should be legal?
So long as you're not breaking my leg or picking my pocket, I don't care what you choose to do with your life. If you're not violating my rights, I have no Right as an Individual to use force against you, or otherwise coerce you to act against your will. Do you believe yourself to have such a Right?
Obviously you are trying to provoke a "collective rights vs. individual rights" discussion, rather than a discussion about the pitfalls of legalized marijuana. So, I'll give you your wish ...
No one disputes your individual rights ... AND no one takes them away (however, we seem to be exceedingly prone to GIVING them away). The purpose of the government is to allow you to exercise your individual rights, while I exercise mine, without interference. However, when the exercise of YOUR rights interfere with the exercise of MY rights, the government must get involved (via laws) and manage the interface. (Mind you, I'm not saying the Government DOESN'T interfere with your practice of individual rights, but they SHOULDN'T). Notionally, you can do anything your little heart desires inside your little box as long as it doesn't interfere with my little box.
You speak of 'common defense', and things like law enforcement, traffic control, etc. as an impingement on your individual rights. They aren't - you haven't lost any rights. You have merely abdicated some of your responsibility (defense of the nation, personal delivery of your mail, etc.) to the government so that they can do it more efficiently and effectively. There is a significant difference between 'rights' and 'responsibility'. I think you are grouping them into a single entity -- and call them 'individual rights'.
There is no such thing as 'collective rights' - only the collection of individual responsibility in order to more efficiently perform that action. (You will note that 'responsibilities' are all active voice, while 'rights' are all passive.)
So, nobody should care if you smoke weed, or mainline heroin, marry a gay man, or drive 100 mph - all things within your box - unless, of course, they interfere with MY box. God wish that were only true ... it is the interference of other individuals that create the impingement on your individual rights. It is those who think they know better what's good for you than you yourself know that create the interference. The far left, with their inherent elitist snobbery, are most prone to this.
From my point of view - I don't care if you smoke, shoot dope, carry a gun, or stick gerbils up your ... well, you know what I mean ... as long as it doesn't interfere with my exercise of MY individual rights. Of course, some will immediately holler that, as a conservative, I have positions that interfere with YOUR box ... but I don't. I oppose abortion, for example, because I believe it interferes with the baby's individual rights. I do not oppose gay marriage, UNLESS it interferes with the practice of my religion (in short, get married in somebody else's church!) Hell, you can marry your dog if you want - just don't ask me to sanctify it.
As the original post clearly illustrates, the legalization of marijuana here in Colorado has significantly interfered with MY box ... and you can expect the same when it comes to your town, as it most assuredly will.
(As a side note, here in Colorado, they are constantly showing the latest development, the latest store, the latest argument, hte latest crime, or the latest recipe about recreational use of marijuana on the nightly news. It's interesting to note that, based on that limited exposure, there is not a single intelligent person in Colorado who smokes marijuana. There are some real idiots - there are some socially disconnected - there are some mentally defective - but not a single person I would hire to cut my lawn - much less my grass. Apparently, the real requirement here is that you must be 21, have poor personal hygiene, not be able to put together three words to make a sentence, and totally incapable of coherent thought)