Several reasons, for one, Rubik's brand cubes are like the worst cubes of all, for two, when his patent/copyright/whateveritwas ran out, he tried copyrighting the colorscheme to avoid other people selling 3x3's, this being after he had earnt more money than I would know what to do with mind you, only thing Rubik's still sells is really merch, nobody buys their cubes unless they don't know how to solve a cube, lololol