Life cards you take early become potential counter cards (since you draw when you take damage in some deck configurations)
These cards are important because they can turn damaged Bench Pokmon into Prize cards or force the opponent to expose a weak support Pokmon
Similarly, the Azorius Control list above plays two copies of Force of Negation, not three, as the card is awful against Hogaak, Humans, and other decks that consist almost entirely of creatures
Planeswalker removal is less common than creature removal (and board wipes often don't hit Planeswalkers), and time spent knocking them out through combat is time that could have been spent attacking you directly
// Flame Star - If a Wizard you control would deal damage to a permanent, it deals double that damage instead
If your opponents have three or more artifacts and enchantments out, youre already pulling in a higher amount of mana than what you have put into casting it