From Game Theory perspective, "not using Linux" is actually the game's equilibrium. Because if you have to choose between a proprietary OS (Windows, macOS) and an FOSS (GNU/Linux, BSD, ...), you'd have to choose the former in order to increase your own utility. If people said they're gonna start using Linux from now on, that wouldn't work, since at least some are willing to "unilaterally deviate" from that decision and use Windows/macOS to gain a boost against others.

If you want people to start using FOSS, you'd have to offer them something they can't have on non-FOSS alternatives.