Okay, but... how is it confusing from the front end if what you're doing is going through the same steps of creating an account? You punch in a login and password in both.
Sure, Plex is doing this extra thing where it's also bringing in centralized content along with your library and it will default to its remote access system if you log in from outside your network. But again, from the front-end that is transparent. You log in and you have your library. If anything they're being a bit too transparent, I've had times where networking stuff got in the way and it took me a minute to notice that Plex was routing my library through their remote access system instead.
I can see objections to it working that way, you trade a (frankly super convenient) way to share content remotely and access content from outside your network without too much hassle for... well, going through someone else's server and having their content sitting alongside yours. But "confusing and difficult" isn't how I'd describe it. It seems to work like any other service, self-hosted or not, as far as the user-facing portions are concerned. I guess I just don't see the confusing part there.