On the bright side, this is actually a demonstration of the extensive work the neovim team has done cleaning up the UI layers. justinmk's comment above goes into more detail, but basically vim has gone from having a single array of characters that gets manipulated by every type of display item to windows with their own positioning and dimensions. In addition, these windows will be exposed via APIs that external GUIs can use.

Vim already had floating windows, why not make them cool/useful if they're there, anyway? :)