The frame of reference makes sense for Toph, and does a good job of presenting her worldview as one that treats visual cues as a seeing might treat, say, telepathic ones. People can talk to Toph about the things she can't experiences, but she's still not experiencing them.

I imagine Aang must have the same experience, to a lesser degree, with everyone else's concept of stuff like "falling" and "height." The Western Air Temple best showed the different frame of reference for airbenders.