To be more clear, this is what manufacturers state their batteries are capable of discharging at. 15 times the capacity.
This is most known in the remote control hobby world. The powerful electric motors eat up a lot of power and need high discharge rates. It is not nonsense. If you don't have a battery capable of the discharge rate the motor demands, it can do 2 things. Slow the motor down and make it sluggish when accelerating or being put under a load. It can also kill the battery in as short as a few cycles. With a LiPO battery this can end up with a not so nice result of setting everything on fire.