Rock Candy Mountain was a proposal for the Storybook Land area, not Holiday Hill. How though is an Alpine mountain next an Alpine castle ridiculous? The design of Sleeping Beauty Castle is not medieval, its references to the Romanesque and Gothic are Victorian era revivalism. So we see an early Victorian era castle at the end of a late Victorian era town. While a castle is not typical of America, its placement plays on an organizational pattern common to Main Streets that create hierarchical focus on an important civic institution. In older towns of the northeast this was typically a church, signifying the religious nature of the community. As American culture shifted with territorial expansion the emphasis changed from religion to republicanism and the courthouse replaced the church as the building of significance, with the railroad station often be another important building in Midwestern towns. A castle is thus a fitting highlight for a Magic Kingdom, it is accepted because it fits into the romantic image and has a similar romantic aesthetic from the same architectural traditions.
That said, this constant attempt to equate Pixar-only lands to Fantasyland ignores that nobody seems to talk about how TRON would make a great addition to Fantasyland. The land is not nor has it ever been just about any and all Disney branded movies.
