I've worked as a tape monkey in a large facility (Camp Foster RASC, Okinawa, circa 1989-90), so I know tapes do work well in the enterprise, but my experience with tapes in the consumer space in the 90s was anything but good. 90% of the tape backups made (using several different formats) using consumer-grade systems were corrupt and worthless.
We took great care with the tapes, but when we checked them (thankfully never needed them, except one occasion), they were mostly all bad.
Optical isn't much more reassuring as a backup media, given that optical discs tend to degrade over time.
If somebody has a tape system that can store terabytes on a cartridge, reliably, for say... $10/TB or less, and the system costs less than $200, I'd look at it, though. Otherwise, it is still more worthwhile just to use hard drives to back up data (even at their inflated prices)