A hook will go through a roller fairlead. If you are holding onto the hook, the hook will go through the fairlead and take your fingers and hand with it. The collar that integral to the bottom of the Safety Thimble is something I came up with after watching a video of a competitor getting his hand sucked through the fairlead when the winch solenoids stuck powering in.
That and a shackle is the safest method for attaching to stuff, steel or soft. The connection is positive and intentional. Before the advent of safety hooks with latches, we used to take electrical tape across the opening of the hook to keep them attached to stuff in an intentional and positive manner. Most of the folks who understood safe recovery were just using a tube thimble with a shackle but that still didn't stop the thimble from going through the fairlead. I fixed that with the Safety Thimble.