The thing is that there is such an enormous amount of research in this area regarding blue light and its impact on melatonin. So I am quite surprised its considered a scam, for over a decade and even when I went to University did a subject on sleep psychology it was believed that blue light impacted melatonin, which impacted sleep, either directly or indirectly.

Unless I am misunderstanding this, this goes against almost every area in which we recommended reducing blue light. Heck Apple market it with their Night Shift function "Studies have shown that exposure to bright blue light in the evening can affect your circadian rhythms and make it harder to fall asleep."

However I agree if you continue to market a product after knowing better than its a scam. But can you also trust the evidence that backtracks science we have considered to be true for so long. You could understand peoples skepticism initially to it being bogus.

You are correct that blue-light impacts melatonin.

This brought people to two conclusions which were proven wrong long ago.

1) the drop in melatonin delays sleep onset, or disrupts sleep

2) wearing blue-light blocking glasses prevents this drop in melatonin.

Bright lights decrease melatonin, the decrease is not large enough to have a significant impact on sleep. Therefore, the blocking of blue-light is unnecessary, and it has never been shown to have an impact on melatonin either.