When the tape drive fails and eats your tape in the process, you better hope you have a second backup or you'll be crying salty salty tears.
I worked in the service center for a tape-drive manufacturer and I would routinely see the drives we got back for repair. They were often taken apart by the customer in a frantic and desperate attempt to get their cassette out. The cassette was almost always still in there though, with multiple feet of tape snagged and wound around everything.