I think the logic is that if anyone can break the IPv6 firewall between your home and the outer net, they can also break the IPv4 NAT router and create the necessary bridges between the networks.
So IOW, what you want is a dumb fridge, not a dumb network. Because in your scenario, it wouldn't matter if your fridge was using IPv4/NAT or IPv6; malcontents will find a way in either way.
As for the whole address space thing, I think people are MUCH more comfortable with IPv4 vs. IPv6 because IPv4 is--at worst--12 digits. That's not too much of a stretch from a telephone number: something we've been memorizing for decades. You can't say the same thing about IPv6 addresses unless they've been SERIOUSLY shortened, and then there's the matter of the letters; at least when telephone numbers use letters, they're used intentionally as a mnemonic.