If your opponents have a fast start, you need to keep them in check
Blue adds great tools like Reflections of Littjara to make extra rats as you cast them, and Homeward Path lets you steal back the donated rats for a fresh round of trouble
Forcing the opponent to discard an instant or sorcery removes an important damage spell, giving -2/-2 to a creature is likely to kill the majority of the creatures they field, and draining two life essentially undoes a spell's worth of damage
Being an efficient answer to Geist of Saint Traft and Timely Reinforcements gives me hope that Bonfire of the Damned could potential revitalize the old Mono Red deck that was so successful in the early days of Innistrad Standard
When there's popularity, there's going to be some rare cards that everyone wants to get their hands on and the most rare in any TCG tends to be limited promo cards
Not to mention, you have the chance to get a nonbasic land with Planar Genesis, which could shift the game in your favor depending on what you hit