ErgicMergic: "I wonder if drug users in the 70's were more responsible or at least more knowledgeable about drugs than the new generation of users today. Teenagers today regularly take 4-6mg Xanax, or other ridiculous doses of benzos, without any benzo tolerance whatsoever. That kind of recklessness would surely kill barbiturate abusers."
Never Knows Best: "It's probably just a matter of a few learning the hard way and then info getting around. Like, the information will spread if it's really needed, but not if it isn't.
Otherwise, it could just be the culture surrounding their use was a bit more conservative and less daring (possible, given the fact that they're readily euphoric, unlike benzos, so nontolerant individuals would start at a more reasonable dose).
That's all just baseless speculation though."
From what I recall of the 70's, prescription drugs just weren't very popular among recreational users. Oh we did them, for sure-- but it was more like something to fall back on if we couldn't find what we really wanted (usually weed, coke, acid, crystal, or junk). I remember doubling or tripling recommended dosages, but not eating pills by the handful.
These are generalizations based on my personal experience, YMMV.