Spears future price is tied to him and how well aggro/midrange Brimaz builds end up doing
(Although I should note that we do push these decks to fringe levels every once in a blue moon.) Utility discard cards, on the other hand, do not necessarily promote the discard decks unto themselves (although they are used if enough resources for the discard deck exists)
It's a go-to sideboard card in artifact decks like Hammer Time or Tron, especially when you need answers but can't afford to play black mana
The deck box is also a real box that you can put fully sleeved decks into, unlike some the old Commander boxes
These have been around since Dark Ascension and have cropped back up in almost every set featuring double-faced cards, but now theres a commander that wants you to put them all in the same deck
Forcing an opponent to lose a card can certainly slow them down and frustrate them especially if they have been holding on to a specific card for several turns