If you have a product that works and people understand it, (and most importantly, it sells), then sometimes it is best to leave it alone and do something else whilst the cash is rolling in.
I'm currently looking at a bottle of beer with a screw top cap. This means that I can flip it off with a bottle opener or 'turn' it open with my hands.
I have just done the latter and in all honesty, I wish I had used a bottle opener. This is because my hand is now in a small degree of pain after the caps rough edges dug into my skin as I twisted.
So, if you are going to make something better - then make it truly better for everyone, not just your idea of better.