Just one draconic attack will generate enough mana to recast a commander like The Ur-Dragon or pay for a massive X spell, such as Torment of Hailfire
Almost every white deck starts here
The combination lacks lifegain and efficient ways to deal with enchantments
Hes got a niche use in politics style decks, but youve gotta respect this creature, otherwise youll be facing down not only the troll, but perhaps those fairies from one of your other opponents.
As a result, if you can kill the (usually heavily guarded and well protected) general, you can gain such an absurdly huge advantage that, even if your opponent is in an amazing position, you can still win
Even outside that ideal scenario, creature-light decks can leverage this as a 2-mana board wipe that might make the opponent discard a card