The same Dropbox that once had a broken login form where a blank password let people in to any account?

Somebody's effort being successful isn't necessarily a good thing. See Facebook.

But it illustrates that "that's easy" or "I can do that by setting up Linux with an X and Y and router rules Z and a dynamic IP Q" isn't the same as user friendly and isn't a bar to commercial success.

Why is everything about commercial success?

As for easy, this is generally achieved by installing the relevant packages, in whatever distribution you're using.

True for at least Debian, Ubuntu, Arch.