I would say the majority of pickups get broken due to mishandling and abuse. Many times removing covers that are stuck to the coil can break the wires. Removing humbucking covers without total removal of solder joints can snag the coils. Pickups left exposed on work benches can attract screws and misc. tools which can damage coils. Most damage to pickups is due to inexperience, lack of control when using screwdrivers, soldering irons and other tools. Improve your work habits and keep a clean work space especially when working with pickups and don’t just throw pickups in a drawer and hope they’ll be O.K. Keep pickups and coils protected by wrapping them in tissue and placing them in a protective container till needed later.