As with most anything, the answer lies in history. The idea that multiple monitors could share the same root window in X is relatively "recent" (Xinerama, but n

As with most anything, the answer lies in history. The idea that multiple monitors could share the same root window in X is relatively "recent" (Xinerama, but now RandR). Before Xinerama, you'd drive multiple monitors on Linux by using separate X screens. Separate X screens have distinct root windows. As a result, you could not move one window from one monitor to the next. Window managers and the specifications surrounding them were built up around this architecture. As a result, there is very meager support in the FreeDesktop WM standards for multiple monitors that share the same root window. Wingo breaks very few of them, but the ones it breaks (e.g., `_NET_WORKAREA`) are pretty important for pagers. It also breaks an implicit assumption that only one workspace is visible at any point in time. So pagers and taskbars are like, "Oh. So you have multiple workspaces visible and they don't all have the same geometry?" Whoops. :-)