I'm a nerd, when i first came up with the Green Path name i went on a bit of a rant about the 'purity' of the route, i had just come out of another re-read of God Emperor of Dune and if you'd read that you'd know all about the Golden Path. In short, the Green Path is the true route, the way the game is meant to be played if you actually pay attention to what the author says, because the truth is you don't have an actual choice, there's the illusion of choice, you're free to choose wrong, but make no mistake, it is wrong. You might think you're making choices, but you're just ripping the story up because you can't handle the weight of the story, at least as far as the dev is concerned. The Green Path is making all the 'choices' Sensei would make, not what you would make.
Anyway, the name stuck, not that i'm complaining exactly, but i was being a bit pretentious when i first coined and ranted on about it like 2 years ago or something. Play however you like, the dev is a douche, sticking to a 100% save to see all the content is smart but if you can't get through some of the more twisted shit in the game, well, do what you want i guess.