The Game of Life is a fun toy, but ultimately unproductive. It does not inherently lead to anything else either; the entire field is a dead end (no matter what Stephen Wolfram says). And, what’s worse, people more or less knew this at the time, and still they let most of the best minds of a generation, as it were, be absorbed into doing nothing but the equivalent of mental navel-gazing.

Thanks, it's interesting you see it that way - but I've never seen that view common among 'hackers'.

So, I doubt that's the factor why the symbol hasn't been more widely-used, emblematically. I instead suspect mixed-feelings about anything ESR proposes, or just more generally the fact that hackers are so varied in interests/behavior that there's little need for a shared emblem. (Though, the glider appeals to a certain mindset, who have & will use it as a symbol, as when it appeared in many remembrances after John Conway's passing.)