Using tape for backing up data that doesn't need to be accessed at a moments notice is a great solution so long as your data sets are large enough to justify the high cost of the drives themselves. If you are backing up about 200Tb or less it's cheaper to build a hard drive array but above that the cost per terabyte for tapes surpasses hard drives and makes a lot of sense. Although I hear managing tape libraries are a pain with how frequently they jam while swapping tapes.