Getting the First Line in Operation

On the news last night the crew reported on a fatal fire in a neighboring town. In the footage there was the hoseline going up the side of the building through the window. I wasn't there and not sure what transpired previously, but I don't think that is a sound firefighting practice.
What is the purpose of the first handline? Put out the fire, protect people in harm or a combination of both? In my department, the primary function of the first line is to protect the interior stairs, which normally will also put out the fire. There are exceptions where the first line will not wind up extinguishing the fire, for example when we have a basement fire in a Brownstone, or an Old Law Tenement where there is an interior entrance to the basement. We really should be bringing that first line to the top of the stairs to protect egress for escaping occupants, then if you are able to make it down the stairs, put out the fire.
Sometimes what looks like an easy job, may in fact be more difficult if we follow the "book". Many people have houses where the garage is attached to the house or under a bedroom, If the interior door is open, we may push fire into uninvolved portions of the house. I had seen a company once enter a basement fire from a rear door and pushed fire up the stairs throughout the rest of the house. It is a discipline, but sometimes we need to do the right thing even if it means we don't "get the fire"