Unfathomable, isn't it? Silly too, no?
It isn't for no reason that the phrase is 'word-of-mouth'. And it's regarded as the best form of marketing.
Do people have the ability to spread the message visually? If they did, we would be a world of visualizers and painters. And perhaps would be spreading visuals looking into each other's eyes :D. Or perhaps would be sketching/painting the whole day to communicate with each other. And yet the obsession with the way a 'logo' looks!