Part of me wants to say because Spike had his hero moment the episode before.But then again, the Buffaloes Twilight teleported onto seemed alright as well. Part of me also wants to think there could have been something more over the course of this season, maybe feature more non-pony connections as well (Reconcile with Gilda, maybe see some more Zebras, some more noble Dragons) all leading up to an epic finale of real friendship saving the day as the non-ponies Tirek thought weren't worth draining ride in to save the day.