It's probably due to the reckless behaviour of early users that LSD got such a bad rap and banned so hard. Not that they should have had to been responsible -- they shouldn't be blamed for stupid government actions -- it's just an unfortunate thing. And early proponents weren't very rigorous and came up with fantastical claims, greatly exaggerating LSD's capabilities. It's still great stuff, just not quite a magical cure-all. Also I'm guessing most ethics systems would have issues with dosing people without their knowledge/consent.
The book also talks of later trips to Mexico where they did mescaline I believe. And how the images they saw, the shapes and patterns, looked exactly like Aztec art.