I understand there is a turn two kill in standard with this little kobold
Creatures usually need a turn to get going, whereas instant and sorcery effects happen immediately upon resolution
Ranked Draft and similar Limited queues affect Limited rank
Its not super cheap or game-ending, but it often delays games or gives one player such an advantage that they end up winning half an hour later
Drawing cards and making land drops are two of the best game actions you can take in MTG, so getting both in one planeswalker makes a commander worth building around
-sigh- Commanders emphasis on color identity in deckbuilding has successfully kept Krrik, Son of Yawgmoth from being a huge problem in the format as a whole, but its still a powerhouse that should be removed or countered on sight against decks with a large or exclusive emphasis on black, as 4 mana can easily become as much as 16, more if life gain enters the equation