After reading the discussion here, I feel that one of the nonsense assumptions is that an RPG must be either a sandbox or a railroad (or, in the best case, some mixture of these two). In reality, it's not two states, or even a linear spectrum. Sandbox and railroad, as characterized in this thread, are only a minor part of a multidimensional space.
What about games that focus on relations and interactions between the PCs, where locations are only a background and the role of the GM is mainly pushing PCs towards each other while introducing conflicts that divide them (with no story in mind, because it's all in the players' choices)? Games like In a Wicked Age, Smallville, Monsterhearts, Hillfolk?
What about games where the majority of setting-building decisions are made by players, not the GM, like in Apocalypse World, Urban Shadows or Dresden Files?
What about games where the story is partially pre-planned and it's known to everybody in advance? With the pre-planning done by the players (eg. Arcs in Chuubo's) or by the game itself (eg. in Polaris)?
What about games where the story is built by players' decisions in a non-linear fashion, like in Microscope?
What about any game that uses strong scene framing, but gives players freedom in how they resolve the scenes and have their choices drive the game forward?