My assumption is that cards from inactive users are wiped over time, but I couldnt find confirmation of this
Deathtouch makes players unwilling to block it with their most important game pieces, and they need effective removal or cards like Angel of Jubilation or Karn's Sylex to shut it down
Black has a lot of great one-sided graveyard hate
If your commander is something like Emry, Lurker of the Loch, you can pitch your hand to Lions Eye Diamond, take the three blue mana to cast Emry, and then on a later turn use her to recover the Lions Eye Diamond plus any other artifacts you pitched
Estinien Varlineau #28 Magic Final Fantasy Art Series Keep track of your collection value over time
That said, it seems more like a naming convention than anything