> Having a public address doesn't worry me. At home I have a firewall at the edge. It is set to block everything incoming.
Concern is privacy, not security. Publicly addressable machine is a bit worse for security (IoT anyone?), but it is a lot worse for privacy.
You already have a public IP address the only difference is if you have a rotating IP address which is orthogonal to IPv6.
The only difference is most ISPs rotate IPv4 but not IPv6.
Heck IPv6 allows more rotation of IPs since it has larger address spaces.
With SLAAC and a random IPv6 you would get at least the same level of privacy. One public IPv4 isn't different from /48 IPv6 network.
I'm not confused about the NAT / firewall distinction, but it might be nice if my ISP didn't have a constant, precise idea of exactly how many connected devices I owned. Can that be _inferred_ with IPv4? Yes, but it's fuzzier.