12277772_ly_reached_the_end_of_its_life__Advantages_of_Disk
[0] Reliability [Advantages of Disk] 
Low MTBF (mean time between failure). Hard disk is invariably significantly more reliable than tape. The only exception to this is that tape can in some instances have better resistance to shock.
Tape vs Disk Backups, has the tape drive finally reached the end of its life
Advantages of Disk