Stretching an attack line dry is a tactic for a set of very specific situations. A couple that come to mind are exterior stairwells, protected interior stairwells, and for tenable halls/corridors from a protected stairwell. With all of these, somebody must be assigned to mind the hose before it's charged and it must be laid out correctly in the stair well. In the photos below, you'll notice the hose on the 'inside' of the stairwell; it should be on the outside. Folds of hose can slip down between the stairs and the wall, banisters, under treads with no risers, under doors and in furniture.

MIND the HOSE!