The Taken King also expanded quite a bit on the storyline as well, infact this and festival of the lost really just kinda tells you even further about the state of humanity in the game. It gives the game more character in my eyes because the guardians are still doing things similar to current humans in their down time. It also kinda gives us an idea of what's left of our culture at this point. Many human cultures have a day of the dead/halloween holiday and logically racing makes sense. Racing is a very human thing to do, we've raced on foot for I'm sure as long as we've been around. From there we progressed to horses, then bicycles, cars, now we have go-carts, bikes, boats, lawnmowers just about anything that moves people will race, so makes sense the guardians would be racing their sparrows. Although I think it would have been cool if they put in a quest line to upgrade a current sparrow into one of the new versions or at least unlock different speed or turning upgrades as we level up with Amanda Holliday, but I'm not complaining just suggesting. =]