Having long legs doesn't make you exempt from deadlifting, but it does require a departure from what may be presented as correct positioning by literature produced by those who've spend no time in actual coaching settings and couldn't pick up a pencil from the floor soundly, let alone a loaded barbell.

Long legs will demand that the hips be higher in the starting position. Attempting to lower the hips in order to increase the back angle as is often said to be 'correct' will result in the hips being too far behind the base to stay on the feet, the shoulders being too far behind the bar to lift it, and/or the knees being too far in front of the bar and blocking its path upward. Sometimes it will be possible for a long-legged athlete to get into a lower-hipped starting position, but they will find it impossible to actually lift the weight off the floor without first elevating the hips to get into the truly correct position. Note that in the cases of very light loads, the lift may be performable, but it will be neither correctly executed nor worthwhile in such cases.

The critical points of the deadlift starting position can remain intact with the longest of legs: The back must be set tightly with a slight reverse curve (i.e. the lumbar spine in its normal curvature and the thoracic spine locked flat) and the scapulae retracted; the shoulders must be slightly in front of the bar and the bar actively pulled into the body; the lifter's weight directed primarily through the heels.