It certainly was ineffective -- I conceded as much in my previous post when I talked about how most people either ignored it or laughed at it. But I'd call that the kids' fault, not DARE's fault. The message was certainly sound, and they had the option of heeding the warning, right?
My guideline is that when something is failing for most people, it's not the peoples' fault, it's the thing's fault.
The information in DARE is, in fact, not sound, which is a big part of why it's not only ineffective, but anti-effective. When kids figure out that they won't die when they have a beer or joint (or whatever the scare tactic du jour is) they realize all at once that they have been lied to. The tendency is for the kids to throw the baby out with the bathwater, ie. they make a perfectly human mistake of realizing (correctly) that the DARE program is an unreliable source of information, and therefore they come to the (incorrect) conclusion that it contains zero valuable information, or worse that the opposite of the information is actually true. In other words, they say to themselves: it turns out taking a puff of weed isn't dangerous and in fact is fun, therefore drugs must be pretty great under most circumstances.
We all see ourselves as the hero of our own story, so I don't begrudge you interpreting your own history as you being prudent and responsible with valuable information that DARE provided you. I'm inviting you to consider that another plausible interpretation is that you're gullible, and lack the curiosity to discover things for yourself because you're too afraid to take risks. I'm not saying it's true, but I am saying it's possible. Back in high school all it would've taken is one slightly pushy friend and one positive experience with drugs, and your life could have turned out radically different, not because you were dumb or irresponsible, but because the experience you arbitrarily happened to have was different.
I tried googling for lies told by DARE, but it's hard to find anything more substantial than third-hand accounts on Yahoo answers or something (that cop said if you smoke a joint, you might DIE, dude!!!) What little I did find [1] makes me think that the information they gave was substantially true, or at least probably true. For example, there's the strong connection between drug abuse and crime, something any policeman or apartment landlord could confirm for you. You can probably dig up some example of a lie they did tell, but all I'm saying is that, by-and-large, it was true.
"One positive experience" with drugs could, indeed, have wrecked my life, but that one experience would never happen and could never happen. The reason is that I wouldn't have done it, pushy friend or no, because I believed what the adults in my life were telling me. Parents, teachers, and DARE officers all said substantially the same thing, and when only idiot kids were telling me different, weighing the relative trustworthiness of those groups was not especially difficult.
There's nothing arbitrary about this. It's called sound reasoning, and part of it is not taking reckless risks. There's a common myth that kids are incapable of it, but I suspect that the truth is closer to them choosing not to practice it.