Saw the title and I already knew IPv6 was still gonna be “not enough adoption” lol.

The overly aggressive lockdown from NAT is not entirely misplaced though. Windows is already notorious for default hosting an atrocious level of protocols that are anywhere between “I can get your NetNTLMv2 hash for free” to “gg ez RCE as SYSTEM user”.

Linux and Unix were also not magically protected either, like every FTP server implementation has had several RCE vulns and it was so bad that Linus himself pointed out how easy it was to abuse buffer overflow vulns even after the addition of NX mem protection with return to libc, several years before ASLR finally landed in Linux and Windows.

Seriously, the early 2000s was the wild west of vulns because everything was still written in C++ so you could just waltz into any binary, find some stack/heap overflow, and you’re on your way to an RCE.

NAT (and firewall) most definitely did prevent millions of users from getting rekt by a metric ton of malware that operated on the ability to connect to those services.