I'm not saying cash is so terrible that a nervous, confused and delicate grandma can't just eat the losses for security. I mean, sure. If you think you're probably going to lose money anyway then <10% a year is better than >10%!
But a 25% allocation by default is just giving money to wealthy men wearing suits. They already own suits, they don't need it. Keep the wealth. Donate it towards lobbying for Georgism instead of new wars, maybe, if you feel like burning a few % on a cause.