Because most of the time, interest in a topic is a function of plausibility. Most nootropics have little or nothing to indicate they work — not even a hint of something plausible.

Of course, it’s possible the scientific community is overlooking something promising. This has happened before. But that’s a dangerous bet for a career scientist to take.

Practically, if you want nootropics that work, and if you want to consume something whose long term side-effects are actually known, get an adderall prescription. (Or, stop trying to neurotically optimize every detail of your life and go outside.)