Solitude Removal According to Wizards, white is the 'color of removal', being the color best equipped to deal with almost any kind of permanent
If a permanent entering the battlefield at the same time as Virtue of Knowledge (including Virtue of Knowledge itself) causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time
That means nobody can counter it, and you can very easily put in a Creature you cant afford otherwise
An early game Pyroclasm is more brutal than Arc Trail and that is otherwise the most brutal thing that can happen to the majority of unpowered cube decks these days
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
Players can't take any actions between the time you make that choice and the time creatures are returned to their owners' hands