Why is it in polaris snowmobiles they are so easy to hotwire you only have to unplug the one cable?

On polaris sleds at least on anything older then 1999, you can just unplug the wire to the ignition (thing you put the key into) and they will rope start like if the key was on? This works great in both my xlt and my xc, and all you have to do is pull on the plug then cord start it. They are the only make of snowmobile ive ever seen that hotwires this easy!