I'm guessing some of the instances are due to neglect. However, as I said, I have 2 launch controllers and the one started to wear pretty badly after less than 20 hours. It was ridiculous. Meanwhile, I have the other launch controller + the replacement with way more time and they both look brand new. They definitely had issues with some of the launch controllers.
No big deal, though, it didn't take me more than 15 minutes on the phone to have a replacement shipped to me.