Not really presumptive if you're aware that like 99% of the adult population are disrupting their circadian rhythm, and natural melatonin production, with screens and artificial light.

But yes, like any supplement, don't take it unless you have a deficiency.

Well the next day drowsiness is one of the most common side effects of taking it too much.

In addition to constantly seeing the same people drinking caffeine products late into the evening, absolutely no exercise and complaining how melatonin does nothing is already enough to presume that they are using it wrong or aren't taking sleep hygiene seriously enough.