BT was peddled with the promise that it will improve a person's health in some way.
Modern foods look good, and grow well, but lack the minerals they are supposed to have.
Its primary promoter was Elmer Heinrich. Heinrich set up a multilevel marketing sales system for the distribution of BT, and was riding high until 1985. Well, you get the idea. It just seemed to be a case of Heinrich being a modern snake oil salesman who took people's money. When Heinrich got in trouble with the FDA for making medicinal claims, his product had to not only be considered worthless, but potentially hazardous to health.