In Giant Oyster's case, a single representative
Among MTGs many viable deckbuilding strategies, going wide is an all-time favorite
With the release of Commander , Wizards of the Coast officially recognized the format, and from here on they would regularly print new sets with the intention of supporting it
We also have lots of poison payoffs like Glistening Sphere, a 3-drop mana rock that proliferates and taps for 3, Distorted Curiosity, 1 mana draw 2, and Corrupted Resolve, a straight up Counterspell that is easier to cast
Maybe it's because the combination of multiple cards in the Command Zone feels a bit like cheating, in some sort of hipster reflex brain
I suppose you could play it with Vampire Hexmage, but why are you jumping through this hoop in particular for one extra turn