DelusionsBeta: I'd be inclined to say both. Wiping large things takes lots of time, wiping large things seven times over takes longer. And of course, if the drive's on its way out, it won't be going at its maximum speed.
The wiping was taking to long. In the end I just said "Screw It" and disassembled it with a hammer. And then a drill press.
@darrel
I back up my data all the time. I don't need any "warnings". This issue was the fault of Seagate. It started when I noticed my drive was coming up with more any more "empty sectors" lately, and so I called a Seagate tech, who advised me to update the drive's firmware (I'd been using WD drives up until that time, and WD internal drives never had upgradeable firmware, though I'm aware that their external "Passport" drives do). After upgrading the firmware, and restarting the system, the BIOS at last detected that the drive was failing it's Reallocated Sectors Count, which is the worst test to fail.
So to sum up, a bad firmware version didn't detect an error until it was too late, which was the fault of the manufacturer.