Suppose that Microsoft created a "good enough" operating system called "Windows Minimum" (WM).
They do that to an extent. Windows XP had 'Starter' edition, and Windows Fundamentals for Legacy PCs, in addition to Embeded, Home and Professional versions. I wish they made the WFfLP available through retail. A stripped down version of XP, made to run on old computers, but still compatible with new (when it was made) software. None of the extras most people didn't need, and ran rather snappy compared to the regular XPs.
If such applications existed, Adobe wouldn't still be in business.
If such vehicles existed, GM wouldn't still be in business. Oh Wait.
To claim that this means NAT provides NO security is simply ridiculous.
On a technical level, NAT does absolutely nothing to protect you. It simply translates one ip to another. Take a typical SOHO internet router for example, it can use a specified IP for a DMZ. That turns off the filtering rules, (they are what protect you) while NAT is still running.
...The computer behind NAT can't be port probed from external address or act as a proper server, big difference.
Those functions are provided by routing/filtering. NAT by itself does nothing to protect you. An open NAT box will send everything to the designated IP.
Any circuit design must contain at least one part which is obsolete, two parts which are unobtainable, and three parts which are still under development.