Does it make a difference to the bike? No. Does it make a difference at all? I think so. Its mainly a safety thing. If you ALWAYS use the shut off switch when you want to kill the engine, then it becomes second nature. The best thing about it being second nature is that if something happens and you need to kill the engine in a hurry, you don't even have to think about it or panic, you just do it. If you never use it, in a panic situation, you'll fumble around. Here's the proof...how many times have you ever tried to use the horn, and end up just hitting the left signal instead?