To be fair, a lot of the people who dismiss it on here have good reasons.
For example, when an illustrator, designer or other artist is looking for that cool, minimalistic visual theme, they generally turn to simple
geometric shapes, i.e. triangles, ellipses and rectangles. When you're trying to make a point in a couple of seconds, you realise how short of choice
you are, believe me! XD
Moreover, there's also the point that these symbols can mean a number of things in other cultures. People like to bag on that "goat horns" sign,
and that appears in manga quite frequently. It would, because it's a sign that conveys surprise in East Asian culture (and originally used to ward
off harmful spirits as the kurana mudra, the older Buddhist forebear of the mano cornuto, or goat sign) There's always umpteen sides to
a coin, right?
Of course there are ways to influence minds on a subconscious level using image and sound, but if the claim is made that there's a grand unified
conspiracy in the entertainment sphere to use these symbols for evil, we need to research it through a clear window. Many of the pioneering theorists
on the "dark" industry had their own agendas, so even then, you can understand why the seemingly ignorant would immediately reject it due to prior