Because as I've already said, they're two entirely different bikes. Apples and onions.
The Rush has tight track geometry and uses a 1" threaded headset & quill stem, and the Tutto is all stretched out with a wacky long top tube, clearance for huge tires, removable cantilever brake mounts and useless belt-drive capability. For a single speed commuter, you're better off with a Surly Steamroller.