Guild leader woes

Why does everyone have a WoW burnout at the same time? Our guild is small enough as it is, and with three more members on hiatus, I will soon be alone again. I don't know what else I can do... I prompt them to RP, I've just started a guild plot, I run dungeons with them, I chat, I'm always available. It's probably just a coincidence, or the inevitable "late phase of addon boredness". But I still feel like I've failed. It sucks.