"Otherwise is rather pointless, I might as well game directly on that machine."
1. I can think of a few reasons to justify the 1 to 1 setup working. First are foremost you can move all the wires, noise, and heat out into the garage. Also you can do a rebuild on your rig out there instead of making a giant mess in your kitchen/livingroom/bedroom. Important once you have a significant other who already hates the gaming you do and the gaming rig you have.
2. Would you rather have your 5 year old, roommate, parent, etc that is going to trash your gaming rig because of the stupid things they do/install/download or would you rather they mess up their old laptop instead?
3. The ability to pick up and go else where in the house to game is badly needed without having to haul all your gear with you. Guests sleeping in the guest room aka your computer den where your rig lives? You want to go "work" in the garage and get away from the family? Want to play games with your kids/friends in the livingroom?
I'd love to be able to put one or many rigs out in the garage and to be able to support a virtual OS on a hardware light device, but I'll take a 1 for 1 streaming over nothing at all.