For one, because you can make pink by mixing light, but you cannnot make brown by mixing light. The fact that brown only exists when you get dark orange but situation in an otherwise light surrounding means that if your color rendering is based on mixing light, brown is literally impossible to make on its own. You cannot, inherently, get any light system to make brown on its own. It either has to frame it with a much lighter color in the screen, or it needs to be situated in a much lighter surrounding.
That's why this video is good educational material: it covers the contextual aspect of color that a lot of folks will have never even thought of. After all, pink is just red that you added white to, why not just add black to orange to get brown ("because that works for paint, but is literally impossible when your medium is light").
That's why this video is good educational material: it covers the contextual aspect of color that a lot of folks will have never even thought of. After all, pink is just red that you added white to, why not just add black to orange to get brown ("because that works for paint, but is literally impossible when your medium is light").