A one-core play has two copies of Will of the West and one copy of Dwarven Tomb (which is obviously useful for fetching things besides Will of the West), so if the player cares about their deck running out there are only three cards to protect it -- and if they come out early, they aren't that useful. A Dwarven Pipe not only would protect your Will of the West from being discarded, but also puts the Will of the West where it would be *most useful*, at the bottom of your deck.
Running out of deck won't automatically lose your game outside a few quests. But if you churn deck quickly and run out of deck, and aren't running a Noldor play-Lords-of-Eldar every turn, your deck will cease to help you. Most of the time, even a 50-card mining deck should be set up to win before they run out of deck, I think. But there's no question Dwarven Pipe can dramatically extend the number of rounds before you run out of deck (plus give you more cracks at those lovely Hidden Caches). In effect both Dwarven Pipe and Will of the West both delay the time until you run out of deck, and do it for the same cost. Will of the West is used in some decks, why not Dwarven Pipe?
Dwarven Pipe isn't as useful as Dunedain Pipe and I think it would still be a little-used card at cost 0. But in a mining deck, why not?