I think it's obvious what that poster means when he says this is the emulator we really don't need, despite it being cool.
The 360 is still easy to find for cheap, works on modern displays, accessories are available and cheap, and the Xbox One can play many of its games (and a lot of the multiplats have native PC versions that are better).
360 games are dirt cheap right now. For the sake of preservation or ability to play these games, yeah this emulator is far less useful than, say, perfecting N64 or Saturn emulation.