In a deeply interactive format playing only sorcery speed is annoying, and it also stops a ton of cards such as Cascade spells, Shelldock Island, Instant Madness cards and Bring to Light
Solitude Removal According to Wizards, white is the 'color of removal', being the color best equipped to deal with almost any kind of permanent
Its an indirect path, but one that adds up over consistent sessions
That means nobody can counter it, and you can very easily put in a Creature you cant afford otherwise
Better yet, since youre casting discarded cards, there are a ton of cards that grant rewards for casting spells from the graveyard
Players can't take any actions between the time you make that choice and the time creatures are returned to their owners' hands