Why is that?
Because I want to believe this place exists. I think a large part of it has to do with the fact that I can see myself there. Not in just a, "Wow, it's lovely there," way either. More basic than that, I'm human and at least some humans reside in that world. They breathe air and ride horses and enjoy a good ale just like I do.
The allure of a fantasy world--and the reader's willingness to suspend their disbelief--is more than the idea of a place that is completely NOT the Earth we call home. While its true that the fantasy worlds I adore have nice decent people as well as assholes just like any era on Earth, they have animals and swings and rain and love just like Earth does...but those worlds are also home to a few things I've never personally encountered, things that my adventurous spirit thinks I would like to encounter.
Sure, fantasy worlds have friendly fire-breathing dragons and toothy vicious ones, but these alien places balance and fit in comfortable places in our minds because they also feature as many warlike kings and ruthless queens as our history books do. Despite familiarity with these character tropes, how they interact and the goals they seek always plays out differently. If you're like me, that's interesting--riveting if the author is good. And along the way, they further feed my fascination not with the potatoes and pumpkins they somehow also have in this otherworld, but with the things that are unique to their world. Things I'd like to try.
Like Nord mead. Or Romulan ale.
The key to suspending disbelief is a mix of engaging characters and plot, convincing storytelling, and familiar elements mixed with fresh ideas. Until I can get my hands on a Time Lord or Hermione's wand, I won't be moving to the USS Enterprise NCC 1701 or to Rivendell. Guess I'll have to settle for being swept away in their stories.