PEOPLES,,,It has nothing to do with the electrical or the performance of the bike. It is all about safety. you see a lot of times on the news you here about cars driving into a store, or a Dunkin Doughnuts? literally.. ok trust me I do not do this sometimes and I ride one handed, so I am not trying to make anyone look bad. I have been in safety training courses here in New Hampshire and they say the proper way to shut of a bike for safety and to keep control is to hit the kill switch 1st. the reason is that if your hand slips of the clutch you still have a hand on the bars for the front brake.
I actually watched a guy at a local Harley dealer buy a Brand new Screaming Eagle. he was sitting on the bike outside after he just bought it with it running and in gear. he went to shut it of at the key not the kill switch, and yes.. he let the clutch out at the same time. away the bike went across the parking lot with him trying to hang on and get control. into the fence he went. sad to watch. he was ok but the bike went into the shop to be repaired. never even left the parking lot.